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Villamarín F, Jardine TD, Bunn SE, Malvasio A, Piña CI, Jacobi CM, Araújo DD, de Brito ES, de Moraes Carvalho F, da Costa ID, Verdade LM, Lara N, de Camargo PB, Miorando PS, Portelinha TCG, Marques TS, Magnusson WE. Body size predicts ontogenetic nitrogen stable-isotope (δ 15N) variation, but has little relationship with trophic level in ectotherm vertebrate predators. Sci Rep 2024; 14:14102. [PMID: 38890338 PMCID: PMC11189434 DOI: 10.1038/s41598-024-61969-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 05/13/2024] [Indexed: 06/20/2024] Open
Abstract
Large predators have disproportionate effects on their underlying food webs. Thus, appropriately assigning trophic positions has important conservation implications both for the predators themselves and for their prey. Large-bodied predators are often referred to as apex predators, implying that they are many trophic levels above primary producers. However, theoretical considerations predict both higher and lower trophic position with increasing body size. Nitrogen stable isotope values (δ15N) are increasingly replacing stomach contents or behavioral observations to assess trophic position and it is often assumed that ontogenetic dietary shifts result in higher trophic positions. Intraspecific studies based on δ15N values found a positive relationship between size and inferred trophic position. Here, we use datasets of predatory vertebrate ectotherms (crocodilians, turtles, lizards and fishes) to show that, although there are positive intraspecific relationships between size and δ15N values, relationships between stomach-content-based trophic level (TPdiet) and size are undetectable or negative. As there is usually no single value for 15N trophic discrimination factor (TDF) applicable to a predator species or its prey, estimates of trophic position based on δ15N in ectotherm vertebrates with large size ranges, may be inaccurate and biased. We urge a reconsideration of the sole use of δ15N values to assess trophic position and encourage the combined use of isotopes and stomach contents to assess diet and trophic level.
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Affiliation(s)
- Francisco Villamarín
- Grupo de Biogeografía y Ecología Espacial (BioGeoE2), Universidad Regional Amazónica Ikiam, Tena, Ecuador.
| | - Timothy D Jardine
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, Canada
| | - Stuart E Bunn
- Australian Rivers Institute, Griffith University, Nathan, QLD, Australia
| | - Adriana Malvasio
- Laboratório de Ecologia e Zoologia (LABECZ), Curso de Engenharia Ambiental, Universidade Federal do Tocantins, Palmas, TO, Brazil
| | - Carlos Ignacio Piña
- Centro de Investigación Científica y de Transferencia Tecnológica a la Producción (Consejo Nacional de Investigaciones Científicas y Técnicas, Provincia de Entre Ríos, Universidad Autónoma de Entre Ríos), Diamante, Argentina
| | | | - Diogo Dutra Araújo
- Laboratório de Ecologia de Vertebrados Terrestres (LEVERT), Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, Brazil
| | | | | | - Igor David da Costa
- Instituto do Noroeste Fluminense de Educação Superior, Universidade Federal Fluminense, Santo Antônio de Pádua, RJ, Brazil
| | | | - Neliton Lara
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, Brazil
| | | | | | - Thiago Costa Gonçalves Portelinha
- Laboratório de Caracterização de Impactos Ambientais (LCIA), Curso de Engenharia Ambiental, Universidade Federal do Tocantins, Palmas, TO, Brazil
| | - Thiago Simon Marques
- Laboratório de Ecologia Aplicada, Núcleo de Estudos Ambientais, Universidade de Sorocaba, Sorocaba, Brazil
| | - William E Magnusson
- Coordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil
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Rogers EJ, Gerson AR. Water restriction increases oxidation of endogenous amino acids in house sparrows (Passer domesticus). J Exp Biol 2024; 227:jeb246483. [PMID: 38380522 PMCID: PMC11093224 DOI: 10.1242/jeb.246483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 02/06/2024] [Indexed: 02/22/2024]
Abstract
Animals can cope with dehydration in a myriad of ways, both behaviorally and physiologically. The oxidation of protein produces more metabolic water per kilojoule than that of fat or carbohydrate, and it is well established that birds increase protein catabolism in response to high rates of water loss. However, the fate of amino acids mobilized in response to water restriction has not been explicitly determined. While protein catabolism releases bound water, we hypothesized that water-restricted birds would also oxidize the resulting amino acids, producing additional water as a product of oxidative phosphorylation. To test this, we fed captive house sparrows (Passer domesticus) 13C-labeled leucine for 9 weeks to label endogenous proteins. We conducted weekly trials during which we measured the physiological response to water restriction as changes in lean mass, fat mass, metabolism and the enrichment of 13C in exhaled CO2 (δ13Cbreath). If water-restricted birds catabolized proteins and oxidized the resulting amino acids, we expected to simultaneously observe greater lean mass loss and elevated δ13Cbreath relative to control birds. We found that water-restricted birds catabolized more lean tissue and also had enriched δ13Cbreath in response to water restriction, supporting our hypothesis. δ13Cbreath, however, varied with metabolic rate and the length of the water restriction period, suggesting that birds may spare protein when water balance can be achieved using other physiological strategies.
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Affiliation(s)
- Elizabeth J. Rogers
- Organismic and Evolutionary Biology Program, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Alexander R. Gerson
- Organismic and Evolutionary Biology Program, University of Massachusetts Amherst, Amherst, MA 01003, USA
- Department of Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA
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Hope SF, Schmitt L, Lourdais O, Angelier F. Nature vs. Nurture: Disentangling the Influence of Inheritance, Incubation Temperature, and Post-Natal Care on Offspring Heart Rate and Metabolism in Zebra Finches. Front Physiol 2022; 13:892154. [PMID: 35620597 PMCID: PMC9127084 DOI: 10.3389/fphys.2022.892154] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/19/2022] [Indexed: 11/16/2022] Open
Abstract
A historic debate in biology is the question of nature vs. nurture. Although it is now known that most traits are a product of both heredity (“nature”) and the environment (“nurture”), these two driving forces of trait development are rarely examined together. In birds, one important aspect of the early developmental environment is egg incubation temperature. Small changes (<1°C) in incubation temperature can have large effects on a wide-array of offspring traits. One important trait is metabolism, because it is related to life-history traits and strategies, organismal performance, and energetic and behavioral strategies. Although it has been shown that embryonic and post-hatch metabolism are related to egg incubation temperature, little is known about how this may vary as a function of genetic differences or post-hatching environmental conditions. Here, we investigated this question in zebra finches (Taeniopygia guttata). We experimentally incubated eggs at two different temperatures: 37.5°C (control), which is optimal for this species and 36.3°C (low), which is suboptimal. We first measured embryonic heart rate as a proxy of embryonic metabolic rate. Then, at hatch, we cross-fostered nestlings to differentiate genetic and pre-hatching factors from post-hatching environmental conditions. When offspring were 30 days-old, we measured their resting metabolic rate (RMR; within the thermoneutral zone) and thermoregulatory metabolic rate (TMR; 12°C; birds must actively thermoregulate). We also measured RMR and TMR of all genetic and foster parents. We found that embryonic heart rate was greater in eggs incubated at the control temperature than those at the low temperature. Further, embryonic heart rate was positively related to genetic father RMR, suggesting that it is both heritable and affected by the pre-natal environment. In addition, we found that post-hatch metabolic rates were positively related to genetic parent metabolic rate, and interactively related to incubation temperature and foster mother metabolic rate. Altogether, this suggests that metabolism and the energetic cost of thermoregulation can be influenced by genetics, the pre-natal environment, and the post-natal environment. Our study sheds light on how environmental changes and parental care may affect avian physiology, as well as which traits may be susceptible to natural selection.
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Chibowski P, Brzeziński M, Suska-Malawska M, Zub K. Diet/Hair and Diet/Faeces Trophic Discrimination Factors for Stable Carbon and Nitrogen Isotopes, and Hair Regrowth in the Yellow-Necked Mouse and Bank Vole. ANN ZOOL FENN 2022. [DOI: 10.5735/086.059.0115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Piotr Chibowski
- Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, PL-02-089 Warsaw, Poland
| | - Marcin Brzeziński
- Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, PL-02-089 Warsaw, Poland
| | - Małgorzata Suska-Malawska
- Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, PL-02-089 Warsaw, Poland
| | - Karol Zub
- Mammal Research Institute, Polish Academy of Sciences, Stoczek 1, PL-17-230 Białowieża, Poland
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Inferences to estimate consumer’s diet using stable isotopes: Insights from a dynamic mixing model. PLoS One 2022; 17:e0263454. [PMID: 35130334 PMCID: PMC8820609 DOI: 10.1371/journal.pone.0263454] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 01/19/2022] [Indexed: 12/04/2022] Open
Abstract
Stable isotope ratios are used to reconstruct animal diet in trophic ecology via mixing models. Several assumptions of stable isotope mixing models are critical, i.e., constant trophic discrimination factor and isotopic equilibrium between the consumer and its diet. The isotopic turnover rate (λ and its counterpart the half-life) affects the dynamics of isotopic incorporation for an organism and the isotopic equilibrium assumption: λ involves a time lag between the real assimilated diet and the diet estimated by mixing models at the individual scale. Current stable isotope mixing model studies consider neither this time lag nor even the dynamics of isotopic ratios in general. We developed a mechanistic framework using a dynamic mixing model (DMM) to assess the contribution of λ to the dynamics of isotopic incorporation and to estimate the bias induced by neglecting the time lag in diet reconstruction in conventional static mixing models (SMMs). The DMM includes isotope dynamics of sources (denoted δs), λ and frequency of diet-switch (ω). The results showed a significant bias generated by the SMM compared to the DMM (up to 50% of differences). This bias can be strongly reduced in SMMs by averaging the isotopic variations of the food sources over a time window equal to twice the isotopic half-life. However, the bias will persist (∼15%) for intermediate values of the ω/λ ratio. The inferences generated using a case study highlighted that DMM enhanced estimates of consumer’s diet, and this could avoid misinterpretation in ecosystem functioning, food-web structure analysis and underlying biological processes.
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Hobson KA, Kuwae T, Drever MC, Easton WE, Elner RW. Biofilm and invertebrate consumption by western sandpipers ( Calidris mauri) and dunlin ( Calidris alpina) during spring migratory stopover: insights from tissue and breath CO 2 isotopic ( δ 13C, δ 15N) analyses. CONSERVATION PHYSIOLOGY 2022; 10:coac006. [PMID: 35198213 PMCID: PMC8857455 DOI: 10.1093/conphys/coac006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 01/13/2022] [Accepted: 02/07/2022] [Indexed: 06/01/2023]
Abstract
Shorebirds use key migratory stopover habitats in spring and fall where body proteins are replenished and lipids stored as fuel for the remaining journey. The Fraser River estuary, British Columbia, Canada, is a critical spring stopover site for hundreds of thousands of migrating western sandpiper, Calidris mauri, and dunlin, Calidris alpina. Intertidal biofilm in spring is an important nutritional source for western sandpiper, with previous isotopic research predicting 45-59% of total diet and 50% of total energy needs. However, these studies relied on isotopic mixing models that did not consider metabolic routing of key dietary macromolecules. Complexity arises due to the mixed macromolecular composition of biofilm that is difficult to characterize isotopically. We expanded on these earlier findings by considering a protein pathway from diet to the body protein pool represented by liver tissue, using a Bayesian mixing model based on δ 13C and δ 15N. We used δ 13C measurements of adipose tissue and breath CO2 to provide an estimate of the carbohydrate and protein δ 13C values of microphytobenthos and used these derived values to better inform the isotopic mixing models. Our results reinforce earlier estimates of the importance of biofilm to staging shorebirds in predicting that assimilated nutrients from biofilm contribute ~35% of the protein budgets for staging western sandpipers (n = 13) and dunlin (n = 11) and at least 41% of the energy budget of western sandpiper (n = 69). Dunlin's ingestion of biofilm appeared higher than anticipated given their expected reliance on invertebrate prey compared to western sandpiper, a biofilm specialist. Isotopic analyses of bulk tissues that consider metabolic routing and that make use of breath CO2 and adipose lipid assays can provide new insights into avian physiology. We advocate further isotopic research to better understand biofilm use by migratory shorebirds in general and as a critical requirement for more effective conservation.
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Affiliation(s)
- Keith A Hobson
- Environment and Climate Change Canada, 11 Innovation Blvd., Saskatoon, Saskatchewan, S7N 3H5, Canada
- Department of Biology, University of Western Ontario, 1151 Richmond St., London, Ontario, N6A 3K7, Canada
| | - Tomohiro Kuwae
- Coastal and Estuarine Environment Research Group, 3-1-1, Nagase, Yokosuka 239-0826, Japan
| | - Mark C Drever
- Environment and Climate Change Canada, 5421 Robertson Rd., Delta, British Columbia, V4K 3Y3, Canada
| | - Wendy E Easton
- Coastal and Estuarine Environment Research Group, 3-1-1, Nagase, Yokosuka 239-0826, Japan
| | - Robert W Elner
- Environment and Climate Change Canada, 5421 Robertson Rd., Delta, British Columbia, V4K 3Y3, Canada
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Cutting KA, Rotella JJ, Grusing E, Waxe JA, Nunlist E, Sowell BF. Nutrient sources for offspring formation: diet-mother and mother-offspring isotope discrimination in domesticated gallinaceous birds. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2021; 57:553-562. [PMID: 34632885 DOI: 10.1080/10256016.2021.1984905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 08/26/2021] [Indexed: 06/13/2023]
Abstract
Stable isotope techniques can be used to assess nutrient acquisition and allocation strategies used to produce offspring. Before stable isotope techniques can be employed, researchers need reliable isotope discrimination values. In this context, isotope discrimination compares the difference in the isotope ratio between the maternal-offspring tissue that occurs during nutrient transfer prior to egg laying. Currently, isotope discrimination values are unknown between the maternal blood constituents - that reflect different temporal scales of integration - and downy feathers of their offspring. In this study, we experimentally derive isotope discrimination relationships between maternal diet-blood constituents for egg laying, and between maternal blood constituents-down feathers of offspring in an experiment with 3 types of domesticated gallinaceous birds raised on known diets. Our experiment is the first to report isotope discrimination values for maternal blood constituents-down of offspring in avian taxa and provides a new sampling technique that is less invasive than previously available as collecting down does not require sampling viable eggs or individuals. Future researchers can use these results to assist in identifying nutrient sources used by adult birds to produce young.
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Affiliation(s)
- Kyle A Cutting
- Red Rock Lakes National Wildlife Refuge, U.S. Fish and Wildlife Service, Lima, MT, USA
- Department of Ecology, Montana State University, Bozeman, MT, USA
| | - Jay J Rotella
- Department of Ecology, Montana State University, Bozeman, MT, USA
| | - Emma Grusing
- Red Rock Lakes National Wildlife Refuge, U.S. Fish and Wildlife Service, Lima, MT, USA
| | - James A Waxe
- The Centennial Sandhills Preserve, The Nature Conservancy, Lima, MT, USA
| | - Erika Nunlist
- Department of Animal and Range Sciences, Montana State University, Bozeman, MT, USA
| | - Bok F Sowell
- Department of Animal and Range Sciences, Montana State University, Bozeman, MT, USA
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Smith RA, Yurkowski DJ, Parkinson KJL, Fort J, Hennin HL, Gilchrist HG, Hobson KA, Mallory ML, Danielsen J, Garbus SE, Hanssen SA, Jónsson JE, Latty CJ, Magnúsdóttir E, Moe B, Parsons GJ, Sonne C, Tertitski G, Love OP. Environmental and life-history factors influence inter-colony multidimensional niche metrics of a breeding Arctic marine bird. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 796:148935. [PMID: 34274678 DOI: 10.1016/j.scitotenv.2021.148935] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 07/05/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
Human industrialization has resulted in rapid climate change, leading to wide-scale environmental shifts. These shifts can modify food web dynamics by altering the abundance and distribution of primary producers (ice algae and phytoplankton), as well as animals at higher trophic levels. Methylmercury (MeHg) is a neuro-endocrine disrupting compound which biomagnifies in animals as a function of prey choice, and as such bioavailability is affected by altered food web dynamics and adds an important risk-based dimension in studies of foraging ecology. Multidimensional niche dynamics (MDND; δ13C, δ15N, THg; total mercury) were determined among breeding common eider (Somateria mollissima) ducks sampled from 10 breeding colonies distributed across the circumpolar Arctic and subarctic. Results showed high variation in MDND among colonies as indicated by niche size and ranges in δ13C, δ15N and THg values in relation to spatial differences in primary production inferred from sea-ice presence and colony migratory status. Colonies with higher sea-ice cover during the pre-incubation period had higher median colony THg, δ15N, and δ13C. Individuals at migratory colonies had relatively higher THg and δ15N, and lower δ13C, suggesting a higher trophic position and a greater reliance on phytoplankton-based prey. It was concluded that variation in MDND exists among eider colonies which influenced individual blood THg concentrations. Further exploration of spatial ecotoxicology and MDND at each individual site is important to examine the relationships between anthropogenic activities, foraging behaviour, and the related risks of contaminant exposure at even low, sub-lethal concentrations that may contribute to deleterious effects on population stability over time. Overall, multidimensional niche analysis that incorporates multiple isotopic and contaminant metrics could help identify those populations at risk to rapidly altered food web dynamics.
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Affiliation(s)
- Reyd A Smith
- University of Windsor, Windsor, Ontario N9B 3P4, Canada.
| | | | | | - Jérôme Fort
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS - La Rochelle University, La Rochelle FR-17000, France
| | - Holly L Hennin
- Environment and Climate Change Canada, Ottawa, Ontario K0A 1H0, Canada
| | - H Grant Gilchrist
- Environment and Climate Change Canada, Ottawa, Ontario K0A 1H0, Canada
| | | | - Mark L Mallory
- cadia University, Wolfville, Nova Scotia B4P 2R6, Canada
| | | | | | | | - Jón Einar Jónsson
- University of Iceland's Research Centre at Snæfellsnes, Hafnargata 3, 340 Stykkishólmur, Iceland
| | - Christopher J Latty
- Arctic National Wildlife Refuge, U.S. Fish and Wildlife Service, Fairbanks, AK 99701, United States
| | - Ellen Magnúsdóttir
- University of Iceland's Research Centre at Snæfellsnes, Hafnargata 3, 340 Stykkishólmur, Iceland
| | - Børge Moe
- Norwegian Institute for Nature Research, Tromsø N-9296, Norway
| | - Glen J Parsons
- Nova Scotia Department of Lands and Forestry, Kentville, Nova Scotia B4N 4E5, Canada
| | | | - Grigori Tertitski
- Institute of Geography of the Russian Academy of Sciences, Moscow 119017, Russia
| | - Oliver P Love
- University of Windsor, Windsor, Ontario N9B 3P4, Canada
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Hewitt DE, Taylor MD, Raoult V, Smith TM, Gaston TF. Diet-tissue discrimination and turnover of δ 13 C and δ 15 N in muscle tissue of a penaeid prawn. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35:e9167. [PMID: 34494325 DOI: 10.1002/rcm.9167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 07/13/2021] [Accepted: 07/16/2021] [Indexed: 06/13/2023]
Abstract
RATIONALE Stable isotopes are used to study trophic and movement ecology in aquatic systems, as they provide spatially distinct, time-integrated signatures of diet. Stable isotope ecology has been used to quantify species-habitat relationships in many important fisheries species (e.g., penaeid prawns), with approaches that typically assume constant values for diet-tissue discrimination and diet-tissue steady state, but these can be highly variable. Here we provide the first report of these processes in Metapenaeus macleayi (eastern school prawn). METHODS Here we explicitly measure and model carbon (δ13 C) and nitrogen (δ15 N) diet-tissue discrimination and turnover in eastern school prawn muscle tissue as a function of experimental time following a change in diet to an isotopically distinct food source. RESULTS Diet-tissue discrimination factors were 5 and 0.6‰ for δ13 C and δ15 N, respectively. Prawn muscle tissue reached an approximate steady state after approximately 50 and 30 days for δ13 C and δ15 N. Half-lives indicated faster turnover of δ15 N (~8 days) than δ13 C (~14 days). CONCLUSIONS Our diet-tissue discrimination factors deviate from 'typical' values with larger values for carbon than nitrogen isotopes, but are generally similar to those measured in other crustaceans. Similarly, our estimates of isotopic turnover align with those in other penaeid species. These findings confirm muscle tissue as a reliable indicator of long-term diet and movement patterns in eastern school prawn.
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Affiliation(s)
- Daniel E Hewitt
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, NSW, Australia
| | - Matthew D Taylor
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, NSW, Australia
- New South Wales Department of Primary Industries, Port Stephens Fisheries Institute, Nelson Bay, NSW, Australia
| | - Vincent Raoult
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, NSW, Australia
| | - Timothy M Smith
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, NSW, Australia
- Centre for Tropical Water and Aquatic Ecosystems Research (TropWATER), James Cook University, Cairns, QLD, Australia
| | - Troy F Gaston
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, NSW, Australia
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Warne RW, Wolf BO. Nitrogen stable isotope turnover and discrimination in lizards. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35:e9030. [PMID: 33332668 DOI: 10.1002/rcm.9030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/16/2020] [Accepted: 12/16/2020] [Indexed: 06/12/2023]
Abstract
RATIONALE Nitrogen stable isotope ratio (δ15 N) processes are not well described in reptiles, which limits reliable inference of trophic and nutrient dynamics. In this study we detailed δ15 N turnover and discrimination (Δ15 N) in diverse tissues of two lizard species, and compared these results with previously published carbon data (δ13 C) to inform estimates of reptilian foraging ecology and nutrient physiology. METHODS We quantified 15 N incorporation and discrimination dynamics over 360 days in blood fractions, skin, muscle, and liver of Sceloporus undulatus and Crotaphytus collaris that differed in body mass. Tissue samples were analyzed on a continuous flow isotope ratio mass spectrometer. RESULTS Δ15 N for plasma and red blood cells (RBCs) ranged between +2.7 and +3.5‰; however, skin, muscle, and liver did not equilibrate, hindering estimates for these somatic tissues. 15 N turnover in plasma and RBCs ranged from 20.7 ± 4 to 303 ± 166 days among both species. Comparison with previously published δ13 C results for these same samples showed that 15 N and 13 C incorporation patterns were uncoupled, especially during winter when hibernation physiology could have played a role. CONCLUSIONS Our results provide estimates of 15 N turnover rates and discrimination values that are essential to using and interpreting isotopes in studies of diet reconstruction, nutrient allocation, and trophic characterization in reptiles. These results also suggest that somatic tissues can be unreliable, while life history shifts in nutrient routing and metabolism potentially cause 15 N and 13 C dynamics to be decoupled.
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Affiliation(s)
- Robin W Warne
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, 62901, USA
| | - Blair O Wolf
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
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Hopkins JB, Ferguson JM, Frederick C, Jerina K. Measuring the impact of corn on mammalian omnivores. J Mammal 2021. [DOI: 10.1093/jmammal/gyaa152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
In human-dominated landscapes throughout the world, wildlife seek out anthropogenic foods because they are high in nutritional value and are consistently available. To investigate this mode of foraging, some researchers use stable isotope analysis to detect these animals in populations and estimate their individual diets. In this study, we develop an integrative approach to measure the proportion of corn, a C4 plant, in the diets of free-ranging mammalian omnivores in C3-dominated ecosystems. We fed captive mice corn, C3 plants, and meat until carbon stable isotopes (δ 13C) from each diet equilibrated in their hair. We then used carbon discrimination factors (Δ 13C; offsets between stable isotope values of consumer tissues and their foods) for mice from these feeding trials and a simple carbon stable isotope mixing model to estimate the corn-based diets of free-ranging American black bears in Wisconsin and brown bears in Slovenia. We used Δ 13C factors for mice to estimate the diets of bears because mouse models are used commonly to study mammalian diet and health, including humans and bears, and body mass has no effect on carbon discrimination factors in monogastric mammalian omnivores. In this study, we found that mice grew fastest, largest, and δ 13C values equilibrated quickest in the hair of mice fed meat versus plant-based diets, suggesting protein quantity (quality was the same) has an effect on Δ 13C. Evidence also suggests that Δ 13C did not increase with animal growth rate as all mice grew throughout the 109-day feeding trials, but isotopic equilibration occurred early while mice still were subadults and was maintained throughout their adult lives. We also found that Δ 13C was highest and most variable in the hair, serum, and liver, of mice fed a mixed diet of C3 plants, supporting our mixed diet hypothesis that states that Δ 13C varies more among tissues of animals fed mixed diets than animals fed nonmixed diets because the former are composed of multiple foods, each with different macromolecular and isotopic compositions. Lastly, we found that corn may have been a more important component of bear diets in Wisconsin than previously thought (adults: x¯ = 29%; x¯ = 33%; subadults: x¯ = 22%; x¯ = 28%), and male brown bears may have fed on 50% more corn (x¯ = 47% versus 31%) in autumn during a year when beechnut availability was low. In a world that is rapidly changing, it is more important than ever to develop the appropriate quantitative tools to measure the impact people have on wildlife. Here, we provide such a tool for monogastric mammalian omnivores and encourage other researchers to do the same for other taxa of interest.
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Affiliation(s)
- John B Hopkins
- Center for Wildlife Studies, North Yarmouth, ME, USA
- University of Ljubljana, Biotechnical Faculty, Department of Forestry and Renewable Forest Resources, Večna pot 83, 1000 Ljubljana, Slovenia
| | - Jake M Ferguson
- School of Life Sciences, University of Hawai’i at Mānoa, Honolulu, HI, USA
| | | | - Klemen Jerina
- University of Ljubljana, Biotechnical Faculty, Department of Forestry and Renewable Forest Resources, Večna pot 83, 1000 Ljubljana, Slovenia
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Carravieri A, Warner NA, Herzke D, Brault-Favrou M, Tarroux A, Fort J, Bustamante P, Descamps S. Trophic and fitness correlates of mercury and organochlorine compound residues in egg-laying Antarctic petrels. ENVIRONMENTAL RESEARCH 2021; 193:110518. [PMID: 33245882 DOI: 10.1016/j.envres.2020.110518] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 06/11/2023]
Abstract
Understanding the drivers and effects of exposure to contaminants such as mercury (Hg) and organochlorine compounds (OCs) in Antarctic wildlife is still limited. Yet, Hg and OCs have known physiological and fitness effects in animals, with consequences on their populations. Here we measured total Hg (a proxy of methyl-Hg) in blood cells and feathers, and 12 OCs (seven polychlorinated biphenyls, PCBs, and five organochlorine pesticides, OCPs) in plasma of 30 breeding female Antarctic petrels Thalassoica antarctica from one of the largest colonies in Antarctica (Svarthamaren, Dronning Maud Land). This colony is declining and there is poor documentation on the potential role played by contaminants on individual physiology and fitness. Carbon (δ13C) and nitrogen (δ15N) stable isotope values measured in the females' blood cells and feathers served as proxies of their feeding ecology during the pre-laying (austral spring) and moulting (winter) periods, respectively. We document feather Hg concentrations (mean ± SD, 2.41 ± 0.83 μg g-1 dry weight, dw) for the first time in this species. Blood cell Hg concentrations (1.38 ± 0.43 μg g-1 dw) were almost twice as high as those reported in a recent study, and increased with pre-laying trophic position (blood cell δ15N). Moulting trophic ecology did not predict blood Hg concentrations. PCB concentrations were very low (Σ7PCBs, 0.35 ± 0.31 ng g-1 wet weight, ww). Among OCPs, HCB (1.02 ± 0.36 ng g-1 ww) and p, p'-DDE (1.02 ± 1.49 ng g-1 ww) residues were comparable to those of ecologically-similar polar seabirds, while Mirex residues (0.72 ± 0.35 ng g-1 ww) were higher. PCB and OCP concentrations showed no clear relationship with pre-laying or moulting feeding ecology, indicating that other factors overcome dietary drivers. OC residues were inversely related to body condition, suggesting stronger release of OCs into the circulation of egg-laying females upon depletion of their lipid reserves. Egg volume, hatching success, chick body condition and survival were not related to maternal Hg or OC concentrations. Legacy contaminant exposure does not seem to represent a threat for the breeding fraction of this population over the short term. Yet, exposure to contaminants, especially Mirex, and other concurring environmental stressors should be monitored over the long-term in this declining population.
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Affiliation(s)
- Alice Carravieri
- Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS- La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle, 17000, France.
| | - Nicholas A Warner
- NILU-Norwegian Institute for Air Research, Fram Centre, Tromsø, NO-9296, Norway; UiT-The Arctic University of Norway, Department of Arctic and Marine Biology, Hansine Hansens veg 18, Tromsø, 9037, Norway
| | - Dorte Herzke
- NILU-Norwegian Institute for Air Research, Fram Centre, Tromsø, NO-9296, Norway; UiT-The Arctic University of Norway, Department of Arctic and Marine Biology, Hansine Hansens veg 18, Tromsø, 9037, Norway
| | - Maud Brault-Favrou
- Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS- La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle, 17000, France
| | - Arnaud Tarroux
- NINA-Norwegian Institute for Nature Research, Fram Centre, Tromsø, NO-9296, Norway
| | - Jérôme Fort
- Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS- La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle, 17000, France
| | - Paco Bustamante
- Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS- La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle, 17000, France; Institut Universitaire de France (IUF), 1 Rue Descartes, Paris, 75005, France
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Furtado R, Granadeiro JP, Campioni L, Silva M, Pereira E, Catry P. Trace elements' reference levels in blood of breeding black-browed albatrosses Thalassarche melanophris from the Falkland Islands. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:39265-39273. [PMID: 32648215 DOI: 10.1007/s11356-020-09928-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 06/29/2020] [Indexed: 06/11/2023]
Abstract
Trace elements' concentration in the ocean is fast growing and is a source of major concern. Being charismatic and at the top of food chains, seabirds are often used as biological monitors of contaminants. We studied the concentration of trace elements in blood of black-browed albatross from the Falklands Islands, which we here show, by tracking with geolocators, forage over most of the Patagonian Shelf. Levels of trace elements were measured in males and females from two different islands. Blood concentrations of trace elements were not significantly different between islands, which is consistent with observations from foraging behavior revealing that birds from both islands foraged in broadly the same areas in the months before sampling. Arsenic and selenium concentrations in females were higher than in males. Sex-related differences in the concentration of these elements may be related to unknown slight differences in diet or to differences in assimilation between sexes. These results provide reference values for monitoring elemental contamination in the Patagonian Shelf Large Marine Ecosystem using black-browed albatrosses, one of the most abundant top predators and a suitable sentinel for the region's environmental health.
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Affiliation(s)
- Ricardo Furtado
- MARE - Marine and Environmental Sciences Centre, ISPA, Instituto Universitário, Lisbon, Portugal.
| | - José Pedro Granadeiro
- CESAM Centre for Environmental and Marine Studies, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal
| | - Letizia Campioni
- MARE - Marine and Environmental Sciences Centre, ISPA, Instituto Universitário, Lisbon, Portugal
| | - Mónica Silva
- Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Eduarda Pereira
- Department of Chemistry and CESAM/REQUIMTE, University of Aveiro, 3810-193, Aveiro, Portugal
| | - Paulo Catry
- MARE - Marine and Environmental Sciences Centre, ISPA, Instituto Universitário, Lisbon, Portugal
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Gelippi M, Popp B, Gauger MFW, Caraveo-Patiño J. Tracing gestation and lactation in free ranging gray whales using the stable isotopic composition of epidermis layers. PLoS One 2020; 15:e0240171. [PMID: 33119639 PMCID: PMC7595409 DOI: 10.1371/journal.pone.0240171] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 09/22/2020] [Indexed: 11/22/2022] Open
Abstract
The isotopic composition of baleen whales' epidermis structural layers can give information about dietary change over time. This study investigated if epidermis layers integrated isotopic values that record physiological changes from gestation to lactation. Epidermis tissues (n = 43) were collected from free ranging lactating female gray whale and calves during the beginning of three breeding seasons. Modelling of δ13C and δ15N values show intra- and inter-individual differences based on epidermal layers, age class and year of sampling. The isotopic composition of mother-calf pairs is correlated, and the estimates of the maximum mother-to-calf isotopic difference was ~1.4‰ for δ13C and between 1 and 1.5‰ for δ15N values. Change in δ15N values among epidermal layers in calves was associated with the transition from fetus to consumption of maternal milk. It is here proposed when lactation influences calf epidermis, δ15N values decrease consistently from the outermost to the innermost layer. However, if a calf was born only few days before collection, epidermis integrates more variable δ15N patterns because gestation still affects the isotopic composition of the layers. The possibility of calculating mother-to-calf nitrogen isotope fractionation, and the regularity of changes between calf layer δ15N values, allowed results of an isotopic clock model to predict the age of each calf when sampled with its mother. This model has the potential to be a straightforward method to estimate the beginning of lactation, therefore calf birth date when direct observations are not feasible. The non-lethal remote collection of epidermis appears to be an effective tool for the study of the physiology of reproduction of baleen whales. The parallel study of the three epidermal structural layers highlighted the importance of considering the unique mother-calf pair physiological status at the time of sampling time when stable isotope results are interpreted.
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Affiliation(s)
- Michelle Gelippi
- Centro de Investigaciones Biológicas del Noroeste, La Paz, B.C.S., México
| | - Brian Popp
- Department of Earth Sciences, University of Hawaii at Manoa, Honolulu, HI, United States of America
| | - Marco F. W. Gauger
- Centro de Investigaciones Biológicas del Noroeste, La Paz, B.C.S., México
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González‐Carcacía JA, Herrera M. LG, Nassar JM. Dietary importance of C3 and CAM food pathways for birds in a Neotropical semiarid zone. Biotropica 2020. [DOI: 10.1111/btp.12798] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- José Antonio González‐Carcacía
- Laboratorio de Biología de Organismos Centro de Ecología Instituto Venezolano de Investigaciones Científicas Altos de Pipe Venezuela
| | - L. Gerardo Herrera M.
- Estación de Biología de Chamela Instituto de Biología Universidad Nacional Autónoma de México San Patricio México
| | - Jafet M. Nassar
- Laboratorio de Biología de Organismos Centro de Ecología Instituto Venezolano de Investigaciones Científicas Altos de Pipe Venezuela
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16
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Studying animal niches using bulk stable isotope ratios: an updated synthesis. Oecologia 2020; 193:27-51. [DOI: 10.1007/s00442-020-04654-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 04/11/2020] [Indexed: 10/24/2022]
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Methionine-balanced diets improve cattle performance in fattening young bulls fed high-forage diets through changes in nitrogen metabolism. Br J Nutr 2020; 124:273-285. [PMID: 32223766 DOI: 10.1017/s0007114520001154] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Ruminants fed high-forage diets usually have a low feed efficiency, and their performances might be limited by methionine (Met) supply. However, the INRA feeding system for growing cattle does not give recommendation for this amino acid (AA). This study aimed to assess the effects of Met-balanced diets on animal performance and N metabolism in young bulls fed high-forage diets formulated at or above protein requirements. Four diets resulting from a factorial arrangement of two protein levels (Normal (13·5 % crude protein) v. High (16·2 % crude protein)) crossed with two Met concentrations (unbalanced (2·0 % of metabolisable protein) v. balanced (2·6 % of metabolisable protein)) were tested on thirty-four fattening Charolais bulls for 7 months before slaughter. Animal growth rate was greater in Met-balanced diets (+8 %; P = 0·02) with a trend for a greater impact in High v. Normal protein diets (P = 0·10). This trend was observed in lower plasma concentrations of branched-chain AA only when Met supplementation was applied to the Normal protein diet (P ≤ 0·06) suggesting another co-limiting AA at Normal protein level. Feed conversion efficiency and N use efficiency were unaffected by Met supplementation (P > 0·05). However, some plasma indicators suggested a better use of AA when High protein diets were balanced v. unbalanced in Met. The proportion of total adipose tissue in carcass increased (+5 percent units; P = 0·03), whereas that of muscle decreased on average 0·8 percent units (P = 0·05) in Met-balanced diets. Our results justify the integration of AA into dietary recommendations for growing cattle.
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Kingsbury KM, Gillanders BM, Booth DJ, Nagelkerken I. Trophic niche segregation allows range-extending coral reef fishes to co-exist with temperate species under climate change. GLOBAL CHANGE BIOLOGY 2020; 26:721-733. [PMID: 31846164 DOI: 10.1111/gcb.14898] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 09/23/2019] [Accepted: 10/17/2019] [Indexed: 06/10/2023]
Abstract
Changing climate is forcing many terrestrial and marine species to extend their ranges poleward to stay within the bounds of their thermal tolerances. However, when such species enter higher latitude ecosystems, they engage in novel interactions with local species, such as altered predator-prey dynamics and competition for food. Here, we evaluate the trophic overlap between range-extending and local fish species along the east coast of temperate Australia, a hotspot for ocean warming and species range extensions. Stable isotope ratios (δ15 N and δ13 C) of muscle tissue and stomach content analysis were used to quantify overlap of trophic niche space between vagrant tropical and local temperate fish communities along a 730 km (6°) latitudinal gradient. Our study shows that in recipient temperate ecosystems, sympatric tropical and temperate species do not overlap significantly in their diet-even though they forage on broadly similar prey groups-and are therefore unlikely to compete for trophic niche space. The tropical and temperate species we studied, which are commonly found in shallow-water coastal environments, exhibited moderately broad niche breadths and local-scale dietary plasticity, indicating trophic generalism. We posit that because these species are generalists, they can co-exist under current climate change, facilitating the existence of novel community structures.
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Affiliation(s)
- Kelsey M Kingsbury
- Southern Seas Ecology Laboratories, School of Biological Sciences, and The Environment Institute, The University of Adelaide, Adelaide, SA, Australia
| | - Bronwyn M Gillanders
- Southern Seas Ecology Laboratories, School of Biological Sciences, and The Environment Institute, The University of Adelaide, Adelaide, SA, Australia
| | - David J Booth
- Fish Ecology Lab, School of Life Sciences, University of Technology Sydney, Ultimo, NSW, Australia
| | - Ivan Nagelkerken
- Southern Seas Ecology Laboratories, School of Biological Sciences, and The Environment Institute, The University of Adelaide, Adelaide, SA, Australia
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Ruhl PJ, Flaherty EA, Dunning JB. Using stable isotopes of plasma, red blood cells, feces, and feathers to assess mature-forest bird diet during the post-fledging period. CAN J ZOOL 2020. [DOI: 10.1139/cjz-2019-0109] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Post-fledging use of early successional habitat by mature-forest birds is well-documented, but the important trophic factors driving this association remain poorly understood. We used stable isotope analysis of plasma, red blood cells, feces, and feathers to determine foraging preferences of three mature-forest bird species captured in 8-year-old clearcuts during the post-fledging period. We did not identify a significant source contribution in any consumer tissue combination using MixSIAR posterior distributions, but the position of consumer tissues in bivariate isotope mixing space suggested that all three mature-forest bird species acted as generalist insectivores during the post-fledging period. Furthermore, estimates of the proportional contribution of fruit to the overall diet were <0.13 for all Scarlet Tanager (Piranga olivacea (J.F. Gmelin, 1789)) tissue types, despite observational evidence of frugivory. We observed significant differentiation in core-niche-space estimates between the two obligate insectivores (Worm-eating Warbler (Helmitheros vermivorum (J.F. Gmelin, 1789)) and Ovenbird (Seiurus aurocapilla (Linnaeus, 1766))), suggesting that clearcuts provided adequate habitat to support the different foraging strategies and invertebrate preferences of both species. By using tissues with short turnover rates to address post-fledging trophic associations of mature-forest birds, we provide a comparison of isotopic values of multiple consumer tissue types in this context.
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Affiliation(s)
- Patrick J. Ruhl
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN 47907, USA
| | - Elizabeth A. Flaherty
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN 47907, USA
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN 47907, USA
| | - John B. Dunning
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN 47907, USA
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN 47907, USA
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20
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Dupont SM, Grace JK, Lourdais O, Brischoux F, Angelier F. Slowing down the metabolic engine: impact of early-life corticosterone exposure on adult metabolism in house sparrows ( Passer domesticus). ACTA ACUST UNITED AC 2019; 222:jeb.211771. [PMID: 31672723 DOI: 10.1242/jeb.211771] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 10/22/2019] [Indexed: 11/20/2022]
Abstract
Whole-organism metabolism is an integrative process that determines not only the energy cost of living but also the energy output that is available for behavioral and physiological processes during the life cycle. Developmental challenge is known to affect growth, development of several organs, and several physiological mechanisms (such as HPA responsiveness, oxidative stress or immunity), which may altogether affect adult metabolism. All of these developmental effects are likely to be mediated by glucocorticoids, but the impact of developmental glucocorticoid exposure on adult metabolism has rarely been studied and the results are equivocal. In this study, we examined the impact of developmental exposure to corticosterone (CORT, the main avian glucocorticoid hormone) on resting metabolic rate (RMR, measured in thermoneutrality, 25°C) and thermoregulatory metabolic rate (TMR, measured in cold challenge conditions, 5°C) in the house sparrow. Following experimental administration of CORT at the nestling stage, house sparrows were kept in captivity until adulthood, when their metabolism was measured. We found that post-natal CORT exposure decreased both RMR and TMR in adult sparrows. This CORT-mediated reduction of metabolism was also associated with a reduced overnight body mass loss. Therefore, our results suggest that developmental CORT exposure can orient the phenotype towards an energy-saving strategy, which may be beneficial in a constraining environmental context.
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Affiliation(s)
- Sophie M Dupont
- Centre d'Etudes Biologiques de Chizé, CNRS-ULR, UMR 7372, 79360 Villiers en Bois, France
| | - Jacquelyn K Grace
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843, USA
| | - Olivier Lourdais
- Centre d'Etudes Biologiques de Chizé, CNRS-ULR, UMR 7372, 79360 Villiers en Bois, France
| | - François Brischoux
- Centre d'Etudes Biologiques de Chizé, CNRS-ULR, UMR 7372, 79360 Villiers en Bois, France
| | - Frédéric Angelier
- Centre d'Etudes Biologiques de Chizé, CNRS-ULR, UMR 7372, 79360 Villiers en Bois, France
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21
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McCabe BJ, Guglielmo CG. Migration Takes Extra Guts for Juvenile Songbirds: Energetics and Digestive Physiology During the First Journey. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00381] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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22
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Muñoz‐Lazo FJJ, Franco‐Trecu V, Naya DE, Martinelli LA, Cruz‐Neto AP. Trophic niche changes associated with habitat fragmentation in a Neotropical bat species. Biotropica 2019. [DOI: 10.1111/btp.12693] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Fernando J. J. Muñoz‐Lazo
- Departamento de Zoologia Instituto de Biociências Universidade Estadual Paulista (UNESP) Rio Claro SP Brasil
| | - Valentina Franco‐Trecu
- Departamento de Ecología y Evolución Facultad de Ciencias Universidad de la República Montevideo Uruguay
| | - Daniel E. Naya
- Departamento de Ecología y Evolución Facultad de Ciencias Universidad de la República Montevideo Uruguay
| | - Luiz A. Martinelli
- Laboratório de Ecologia Isotópica Centro de Energia Nuclear para a Agricultura (CENA) Universidade de São Paulo (USP) Piracicaba SP Brasil
| | - Ariovaldo P. Cruz‐Neto
- Departamento de Zoologia Instituto de Biociências Universidade Estadual Paulista (UNESP) Rio Claro SP Brasil
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23
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Silva MA, Borrell A, Prieto R, Gauffier P, Bérubé M, Palsbøl PJ, Colaço A. Stable isotopes reveal winter feeding in different habitats in blue, fin and sei whales migrating through the Azores. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181800. [PMID: 31598219 PMCID: PMC6731742 DOI: 10.1098/rsos.181800] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 07/23/2019] [Indexed: 06/10/2023]
Abstract
Knowing the migratory movements and behaviour of baleen whales is fundamental to understanding their ecology. We compared δ15N and δ13C values in the skin of blue (Balaenoptera musculus), fin (Balaenoptera physalus) and sei (Balaenoptera borealis) whales sighted in the Azores in spring with the values of potential prey from different regions within the North Atlantic using Bayesian mixing models to investigate their trophic ecology and migration patterns. Fin whale δ15N values were higher than those recorded in blue and sei whales, reflecting feeding at higher trophic levels. Whales' skin δ15N and δ13C values did not reflect prey from high-latitude summer foraging grounds; instead mixing models identified tropical or subtropical regions as the most likely feeding areas for all species during winter and spring. Yet, differences in δ13C values among whale species suggest use of different regions within this range. Blue and sei whales primarily used resources from the Northwest African upwelling and pelagic tropical/subtropical regions, while fin whales fed off Iberia. However, determining feeding habitats from stable isotope values remains difficult. In conclusion, winter feeding appears common among North Atlantic blue, fin and sei whales, and may play a crucial role in determining their winter distribution. A better understanding of winter feeding behaviour is therefore fundamental for the effective conservation of these species.
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Affiliation(s)
- Mónica A. Silva
- Okeanos Centre & Institute of Marine Research (IMAR), University of the Azores, 9901-862 Horta, Portugal
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
- Marine and Environmental Sciences Centre Açores (MARE), Department of Oceanography and Fisheries, 9901-862 Horta, Portugal
| | - Asunción Borrell
- Institute of Biodiversity Research (IRBio) & Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Rui Prieto
- Okeanos Centre & Institute of Marine Research (IMAR), University of the Azores, 9901-862 Horta, Portugal
- Marine and Environmental Sciences Centre Açores (MARE), Department of Oceanography and Fisheries, 9901-862 Horta, Portugal
| | - Pauline Gauffier
- Institute of Biodiversity Research (IRBio) & Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Martine Bérubé
- Groningen Institute of Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
- Centre for Coastal Studies, Provincetown, MA 02657, USA
| | - Per J. Palsbøl
- Groningen Institute of Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
- Centre for Coastal Studies, Provincetown, MA 02657, USA
| | - Ana Colaço
- Okeanos Centre & Institute of Marine Research (IMAR), University of the Azores, 9901-862 Horta, Portugal
- Marine and Environmental Sciences Centre Açores (MARE), Department of Oceanography and Fisheries, 9901-862 Horta, Portugal
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The Importance of Isotopic Turnover for Understanding Key Aspects of Animal Ecology and Nutrition. DIVERSITY-BASEL 2019. [DOI: 10.3390/d11050084] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Stable isotope-based methods have proved to be immensely valuable for ecological studies ranging in focus from animal movements to species interactions and community structure. Nevertheless, the use of these methods is dependent on assumptions about the incorporation and turnover of isotopes within animal tissues, which are oftentimes not explicitly acknowledged and vetted. Thus, the purpose of this review is to provide an overview of the estimation of stable isotope turnover rates in animals, and to highlight the importance of these estimates for ecological studies in terrestrial, freshwater, and marine systems that may use a wide range of stable isotopes. Specifically, we discuss 1) the factors that contribute to variation in turnover among individuals and across species, which influences the use of stable isotopes for diet reconstructions, 2) the differences in turnover among tissues that underlie so-called ‘isotopic clocks’, which are used to estimate the timing of dietary shifts, and 3) the use of turnover rates to estimate nutritional requirements and reconstruct histories of nutritional stress from tissue isotope signatures. As we discuss these topics, we highlight recent works that have effectively used estimates of turnover to design and execute informative ecological studies. Our concluding remarks suggest several steps that will improve our understanding of isotopic turnover and support its integration into a wider range of ecological studies.
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25
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Farly L, Hudon C, Cattaneo A, Cabana G. Seasonality of a Floodplain Subsidy to the Fish Community of a Large Temperate River. Ecosystems 2019. [DOI: 10.1007/s10021-019-00374-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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26
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Dick MF, Alcantara-Tangonan A, Shamli Oghli Y, Welch KC. Metabolic partitioning of sucrose and seasonal changes in fat turnover rate in ruby-throated hummingbirds (Archilochus colubris). J Exp Biol 2019; 223:jeb.212696. [DOI: 10.1242/jeb.212696] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 12/09/2019] [Indexed: 11/20/2022]
Abstract
Hummingbirds fuel their high energy needs with the fructose and glucose in their nectar diets. These sugars are used to fuel both immediate energy needs and to build fat stores to fuel future fasting periods. Fasting hummingbirds can deplete energy stores in only hours and need to be continuously replacing these stores while feeding and foraging. If and how hummingbirds partition dietary fructose and glucose towards immediate oxidation versus fat storage is unknown. Using a chronic stable isotope tracer methodology, we examined if glucose or fructose are preferentially used for de novo lipogenesis in ruby-throated hummingbirds (Archilochus colubris.) Potential seasonal changes were correlated with variation in the overall daily energy expenditure. We fed ruby-throated hummingbirds sucrose-based diets enriched with 13C on either the glucose or the fructose portion of the disaccharide for 5 days. Isotopic incorporation into fat stores was measured via the breath 13C signature while fasting (oxidizing fat) during the winter and summer seasons. We found greater isotopic enrichment of fat stores when glucose was labelled compared to fructose, suggesting preference for glucose as a substrate for fatty acid synthesis. We also found a seasonal effect on fat turnover rate. Faster turnover rates occurred during the summer months when birds maintained lower body mass, fat stores and exhibited higher daily nectar intake compared to winter. This demonstrates that fat turnover rate can substantially vary with changing energy expenditure and body composition, however the partitioning of sucrose towards de novo fatty acid synthesis remains constant.
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Affiliation(s)
- Morag F. Dick
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada
| | - Antonio Alcantara-Tangonan
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada
| | - Yazan Shamli Oghli
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada
| | - Kenneth C. Welch
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada
- Department of Cell & Systems Biology, University of Toronto, 27 King's College Circle, Toronto, ON, M5S 3G5, Canada
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Shoji A, Elliott KH, Aris-Brosou S, Mizukawa H, Nakayama SMM, Ikenaka Y, Ishizuka M, Kuwae T, Watanabe K, Escoruela Gonzalez J, Watanuki Y. Biotransport of metallic trace elements from marine to terrestrial ecosystems by seabirds. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2019; 38:106-114. [PMID: 30284322 DOI: 10.1002/etc.4286] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 08/20/2018] [Accepted: 09/28/2018] [Indexed: 06/08/2023]
Abstract
Physical systems, such as currents and winds, have traditionally been considered responsible for transporting contaminants. Although evidence is mounting that animals play a role in this process through their movements, we still know little about how such contaminant biotransport occurs and the extent of effects at deposition sites. In the present study, we address this question by studying how rhinoceros auklets (Cerorhinca monocerata), a seabird that occurs in immense colonies (∼300 000 pairs at our study site, Teuri Island), affect contaminant levels at their colony and at nearby sites. More specifically, we hypothesize that contaminants are transported and deposited by seabirds at their colony and that these contaminants are passed on locally to the terrestrial ecosystem. To test this hypothesis, we analyzed the concentration of 9 heavy metal and metalloids, as well as δ13 C and δ15 N stable isotopes, in bird tissues, plants, and soil, both within and outside of the colony. The results show that rhinoceros auklets transport marine-derived mercury (Hg), possibly from their wintering location, and deposit Hg via their feces at their breeding site, thereby contaminating plants and soils within the breeding colony. The present study confirms not only that animals can transport contaminants from marine to terrestrial ecosystems, potentially over unexpectedly long distances, but also that bird tissues contribute locally to plant contamination. Environ Toxicol Chem 2019;38:106-114. © 2018 SETAC.
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Affiliation(s)
- A Shoji
- Graduate School of Fisheries Sciences, Hokkaido University, Hokkaido, Japan
- Department of Zoology, Oxford University, Oxford, United Kingdom
| | - K H Elliott
- Department of Natural Resource Sciences, McGill University, Ste. Anne de Bellevue, Quebec, Canada
| | - S Aris-Brosou
- Departments of Biology and Statistics, University of Ottawa, Ottawa, Ontario, Canada
| | - H Mizukawa
- Department of Environmental Veterinary Sciences, Laboratory of Toxicology, Hokkaido University, Hokkaido, Japan
| | - S M M Nakayama
- Department of Environmental Veterinary Sciences, Laboratory of Toxicology, Hokkaido University, Hokkaido, Japan
| | - Y Ikenaka
- Department of Environmental Veterinary Sciences, Laboratory of Toxicology, Hokkaido University, Hokkaido, Japan
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - M Ishizuka
- Department of Environmental Veterinary Sciences, Laboratory of Toxicology, Hokkaido University, Hokkaido, Japan
| | - T Kuwae
- Coastal and Estuarine Environment Research Group, Port and Airport Research Institute, Yokosuka, Japan
| | - K Watanabe
- Coastal and Estuarine Environment Research Group, Port and Airport Research Institute, Yokosuka, Japan
| | - J Escoruela Gonzalez
- Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Universitat de Barcelona, Barcelona, Spain
| | - Y Watanuki
- Graduate School of Fisheries Sciences, Hokkaido University, Hokkaido, Japan
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Buelow CA, Reside AE, Baker R, Sheaves M. Stable isotopes reveal opportunistic foraging in a spatiotemporally heterogeneous environment: Bird assemblages in mangrove forests. PLoS One 2018; 13:e0206145. [PMID: 30439959 PMCID: PMC6237324 DOI: 10.1371/journal.pone.0206145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 10/08/2018] [Indexed: 11/19/2022] Open
Abstract
Environmental heterogeneity can foster opportunistic foraging by mobile species, resulting in generalized resource and habitat use. Determining species' food web roles is important to fully understand how ecosystems function, and stable isotopes can provide insight into the foraging ecology of bird assemblages. We investigated flexibility of food choice in mangrove bird assemblages of northeast Australia by determining whether species' carbon and nitrogen isotopic values corresponded to foraging group classification described in the literature, such as groups of species that are omnivorous or insectivorous. Subsequently, we evaluated foraging group isotopic niche size, overlap, degree of individual specialisation, and the probable proportions of coastal resources that contribute to their collective diets. We found that mangrove birds are more opportunistic when foraging than expected from previous diet studies. Importantly, relationships between the dietary diversity of species within a foraging group and isotopic niche size are spatially inconsistent, making inferences regarding foraging strategies difficult. However, quantifying individual specialisation and determining the probable relative contributions of coastal resources to the collective diet of isotope-based foraging groups can help to differentiate between specialised and generalised foraging strategies. We suggest that flexibility in mangrove bird foraging strategy occurs in response to environmental heterogeneity. A complementary approach that combines isotopic analysis with other dietary information (collated from previous diet studies using visual observation or gut content analyses) has provided useful insight to how bird assemblages partition resources in spatiotemporally heterogeneous environments.
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Affiliation(s)
- Christina A. Buelow
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Centre for Tropical Water & Aquatic Ecosystem Research (TropWATER), James Cook University, Townsville, Queensland, Australia
| | - April E. Reside
- Centre for Biodiversity and Conservation Science, The University of Queensland, Brisbane, Queensland, Australia
| | - Ronald Baker
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Centre for Tropical Water & Aquatic Ecosystem Research (TropWATER), James Cook University, Townsville, Queensland, Australia
- Dauphin Island Sea Lab, The University of South Alabama, Dauphin Island, Alabama, United States
| | - Marcus Sheaves
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Centre for Tropical Water & Aquatic Ecosystem Research (TropWATER), James Cook University, Townsville, Queensland, Australia
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Nuche‐Pascual MT, Lazo JP, Ruiz‐Cooley RI, Herzka SZ. Amino acid-specific δ 15N trophic enrichment factors in fish fed with formulated diets varying in protein quantity and quality. Ecol Evol 2018; 8:9192-9217. [PMID: 30377494 PMCID: PMC6194260 DOI: 10.1002/ece3.4295] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 05/07/2018] [Accepted: 05/20/2018] [Indexed: 11/10/2022] Open
Abstract
Compound-specific isotope analysis (CSIA) of amino acids (AAs) in consumer tissues is a developing technique with wide-ranging applications for identifying nitrogen (N) sources and estimating animal trophic level. Controlled experiments are essential for determining which dietary conditions influence variability in N stable isotopes (δ15N) trophic enrichment factors in bulk tissue (TEFbulk) and AAs (TEFAA). To date, however, studies have not independently evaluated the effect of protein quantity and quality (digestibility) on TEFs, complicating the application of AA-δ15N values for estimating trophic levels. We conducted a 98-d feeding experiment using five formulated isoenergetic feeds prepared with a high-quality protein source to evaluate the effect of protein quantity and quality on TEFs of liver and muscle tissues of juvenile Pacific yellowtail (Seriola lalandi), a carnivorous fish species. We decreased protein digestibility using well-established protocols that do not change AA profiles. Growth rates were higher in diets with higher protein content, and isotopic equilibrium was reached for both fish tissues and all treatments. Protein quantity and quality influenced isotope discrimination depending on tissue type and AA. In liver tissue, bulk TEFs showed a limited but significant relationship with protein quality, but did not differ with protein quantity or quality in muscle. None of the pre-established source AAs (Lys, Met, Phe, and Gly) TEFs varied significantly with protein quantity or quality in liver tissue. However, in muscle tissue, TEFPhe increased significantly with protein content and decreased in response to reduced digestibility, indicating it may not serve as proxy for baseline isotopic values used to calculate trophic level. Among trophic AAs, TEFLeu decreased significantly with increasing protein quantity in liver tissue, while both Leu and Ile TEFs decreased with lower protein digestibility in muscle tissue. Our results indicate that CSIA-AA in liver tissue provides more robust source and trophic AA-δ15N values than in muscle.
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Affiliation(s)
- M. Teresa Nuche‐Pascual
- Departamento de Oceanografía BiológicaCentro de Investigación Científica y de Educación Superior de Ensenada (CICESE)EnsenadaMéxico
| | | | | | - Sharon Z. Herzka
- Departamento de Oceanografía BiológicaCentro de Investigación Científica y de Educación Superior de Ensenada (CICESE)EnsenadaMéxico
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Fowler DN, Webb EB, Baldwin FB, Vrtiska MP, Hobson KA. A multi-isotope (δ13C, δ15N, δ34S, δ2H) approach to establishing migratory connectivity in lesser snow geese: Tracking an overabundant species. PLoS One 2018; 13:e0203077. [PMID: 30142189 PMCID: PMC6108521 DOI: 10.1371/journal.pone.0203077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/14/2018] [Indexed: 11/18/2022] Open
Abstract
Expanding populations of North American midcontinent lesser snow geese (Anser caerulescens caerulescens) have potential to alter ecosystems throughout the Arctic and subarctic where they breed. Efforts to understand origins of harvested lesser snow geese to better inform management decisions have traditionally required mark-recapture approaches, while aerial photographic surveys have typically been used to identify breeding distributions. As a potential alternative, isotopic patterns that are metabolically fixed within newly grown flight feathers following summer molting could provide inferences regarding geographic breeding origin of individuals, without the need for prior capture. Our objective was to assess potential to use four stable isotopes (δ13C, δ15N, δ34S, δ2H) from feather material to determine breeding origins. We obtained newly grown flight feathers from individuals during summer banding at three Arctic and two subarctic breeding colonies in 2014 (n = 56) and 2016 (n = 45). We used linear discriminant analyses to predict breeding origins from models using combinations of stable isotopes as predictors and evaluated model accuracy when predicting colony, subregion, or subpopulation levels. We found a strong inverse relationship between δ2H values and increasing latitude (R2 = 0.83), resulting in differences (F4, 51 = 90.41, P < 0.0001) among sampled colonies. No differences in δ13C or δ15N were detected among colonies, although δ34S in Akimiski Island, Baffin Island, and Karrak Lake were more enriched (F4, 51 = 11.25, P < 0.0001). Using δ2H values as a predictor, discriminant analyses improved accuracy in classification level as precision decreased [model accuracy = 67% (colony), 88% (subregion), 94% (subpopulation)]. Application of the isotopic methods we describe could be used to provide an alternative monitoring method of population metrics, such as overall breeding population distribution, region-specific productivity and migratory connectivity that are informative to management decision makers and provide insight into cross-seasonal effects that may influence migratory behavior.
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Affiliation(s)
- Drew N. Fowler
- Missouri Cooperative Fish and Wildlife Research Unit, School of Natural Resources, University of Missouri, Columbia, Missouri, United States of America
- * E-mail:
| | - Elisabeth B. Webb
- U. S. Geological Survey, Missouri Cooperative Fisheries and Wildlife Research Unit, School of Natural Resources, University of Missouri, Columbia, Missouri, United States of America
| | - Frank B. Baldwin
- Department of Sustainable Development, Province of Manitoba, Winnipeg, Manitoba, Canada
| | - Mark P. Vrtiska
- Nebraska Game and Parks Commission, Lincoln, Nebraska, United States of America
| | - Keith A. Hobson
- Department of Biology, Western University, London, Ontario, Canada
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Cloyed CS, Eason PK, Dell AI. The thermal dependence of carbon stable isotope incorporation and trophic discrimination in the domestic cricket, Acheta domesticus. JOURNAL OF INSECT PHYSIOLOGY 2018; 107:34-40. [PMID: 29432766 DOI: 10.1016/j.jinsphys.2018.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/12/2018] [Accepted: 02/08/2018] [Indexed: 06/08/2023]
Abstract
Stable isotopes are valuable tools in physiological and ecological research, as they can be used to estimate diet, habitat use, and resource allocation. However, in most cases a priori knowledge of two key properties of stable isotopes is required, namely their rate of incorporation into the body (incorporation rate) and the change of isotope values between consumers and resources that arises during incorporation of the isotopes into the consumer's tissues (trophic discrimination). Previous studies have quantified these properties across species and tissue types, but little is known about how they vary with temperature, a key driver of many biological rates and times. Here, we explored for the first time how temperature affects both carbon incorporation rate and trophic discrimination via growth rates, using the domestic cricket, Acheta domesticus. We raised crickets at 16 °C, 21 °C, and 26 °C and showed that temperature increased carbon isotope incorporation rate, which was driven by both an increased growth rate and catabolism at higher temperatures. Trophic discrimination of carbon isotopes decreased at higher temperatures, which we attributed to either lower activation energies needed to synthesize non-essential amino acids at higher temperatures or the increased utilization of available resources of consumers at higher temperatures. Our results demonstrate that temperature is a key driver of both carbon isotope incorporation rate and trophic discrimination, via mechanisms that likely persist across all ectotherms. Experiments to determine incorporation rates and trophic discrimination factors in ectotherms must include temperature as a major factor, and natural variation in temperature might have significant effects on these isotopic properties that then can affect inferences made from isotope values.
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Affiliation(s)
- Carl S Cloyed
- National Great Rivers Research and Education Center, East Alton, IL 62024, United States; Washington University in St. Louis, Department of Biology, St. Louis, MO 63130, United States.
| | - Perri K Eason
- University of Louisville, Department of Biology, Louisville, KY 40292, United States
| | - Anthony I Dell
- National Great Rivers Research and Education Center, East Alton, IL 62024, United States; Washington University in St. Louis, Department of Biology, St. Louis, MO 63130, United States
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Carter WA, Cooper-Mullin C, McWilliams SR. Turnover of muscle lipids and response to exercise differ between neutral and polar fractions in a model songbird, the zebra finch. ACTA ACUST UNITED AC 2018; 221:jeb.168823. [PMID: 29444847 DOI: 10.1242/jeb.168823] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 02/01/2018] [Indexed: 01/12/2023]
Abstract
The turnover rates of tissues and their constituent molecules give us insights into animals' physiological demands and their functional flexibility over time. Thus far, most studies of this kind have focused on protein turnover, and few have considered lipid turnover despite an increasing appreciation of the functional diversity of this class of molecules. We measured the turnover rates of neutral and polar lipids from the pectoralis muscles of a model songbird, the zebra finch (Taeniopygia guttata, N=65), in a 256 day C3/C4 diet shift experiment, with tissue samples taken at 10 time points. We also manipulated the physiological state of a subset of these birds with a 10 week flight training regimen to test the effect of exercise on lipid turnover. We measured lipid δ13C values via isotope ratio mass spectrometry (IRMS) and estimated turnover in different fractions and treatment groups with non-linear mixed-effect regression. We found a significant difference between the mean retention times (τ) of neutral and polar lipids (t119=-2.22, P=0.028), with polar lipids (τ=11.80±1.28 days) having shorter retention times than neutral lipids (τ=19.47±3.22 days). When all birds were considered, we also found a significant decrease in the mean retention time of polar lipids in exercised birds relative to control birds (difference=-2.2±1.83 days, t56=-2.37, P=0.021), but not neutral lipids (difference=4.2± 7.41 days, t56=0.57, P=0.57). A larger, more variable neutral lipid pool and the exposure of polar lipids in mitochondrial membranes to oxidative damage and increased turnover provide mechanisms consistent with our results.
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Affiliation(s)
- Wales A Carter
- Department of Natural Resources Science, University of Rhode Island, Kingston, RI 02881, USA
| | - Clara Cooper-Mullin
- Department of Natural Resources Science, University of Rhode Island, Kingston, RI 02881, USA
| | - Scott R McWilliams
- Department of Natural Resources Science, University of Rhode Island, Kingston, RI 02881, USA
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33
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Welch KC, Myrka AM, Ali RS, Dick MF. The Metabolic Flexibility of Hovering Vertebrate Nectarivores. Physiology (Bethesda) 2018; 33:127-137. [DOI: 10.1152/physiol.00001.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Foraging hummingbirds and nectar bats oxidize both glucose and fructose from nectar at exceptionally high rates. Rapid sugar flux is made possible by adaptations to digestive, cardiovascular, and metabolic physiology affecting shared and distinct pathways for the processing of each sugar. Still, how these animals partition and regulate the metabolism of each sugar and whether this occurs differently between hummingbirds and bats remain unclear.
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Affiliation(s)
- Kenneth C. Welch
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada
- Center for the Neurobiology of Stress, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Alexander M. Myrka
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Raafay Syed Ali
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Morag F. Dick
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada
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Boggie MA, Carleton SA, Collins DP, Vradenburg J, Sroka CJ. Using stable isotopes to estimate reliance on agricultural food subsidies and migration timing for a migratory bird. Ecosphere 2018. [DOI: 10.1002/ecs2.2083] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Affiliation(s)
- Matthew A. Boggie
- Department of Biology; New Mexico State University; Las Cruces New Mexico 88003 USA
| | - Scott A. Carleton
- U.S. Fish and Wildlife Service; Migratory Bird Office, Region 2; Albuquerque New Mexico 87103 USA
| | - Daniel P. Collins
- U.S. Fish and Wildlife Service; Migratory Bird Office, Region 2; Albuquerque New Mexico 87103 USA
| | - John Vradenburg
- Kalamath Basin National Wildlife Refuge Complex; Tulelake California 96134 USA
| | - Christopher J. Sroka
- Department of Economics, Applied Statistics, & International Business; College of Business; New Mexico State University; Las Cruces New Mexico 88003 USA
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35
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Catry T, Lourenço PM, Granadeiro JP. Quantifying population size of migrant birds at stopover sites: Combining count data with stopover length estimated from stable isotope analysis. Methods Ecol Evol 2017. [DOI: 10.1111/2041-210x.12913] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Teresa Catry
- Faculdade de Ciências da Universidade de LisboaDepartamento de Biologia AnimalCentro de Estudos do Ambiente e do Mar Lisboa Portugal
| | - Pedro M. Lourenço
- Faculdade de Ciências da Universidade de LisboaDepartamento de Biologia AnimalCentro de Estudos do Ambiente e do Mar Lisboa Portugal
| | - José P. Granadeiro
- Faculdade de Ciências da Universidade de LisboaDepartamento de Biologia AnimalCentro de Estudos do Ambiente e do Mar Lisboa Portugal
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36
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Doi H, Akamatsu F, González AL. Starvation effects on nitrogen and carbon stable isotopes of animals: an insight from meta-analysis of fasting experiments. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170633. [PMID: 28879005 PMCID: PMC5579121 DOI: 10.1098/rsos.170633] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 07/26/2017] [Indexed: 05/25/2023]
Abstract
Nitrogen and carbon stable isotopic compositions (δ15N and δ13C) of consumers have been used for physiological and food web studies. Previous studies have shown δ15N and δ13C values are affected by several biological and environmental factors during starvation, but the generality of the effect of starvation on δ15N and δ13C values has not yet been tested. Here, we performed a meta-analysis to evaluate the effects of starvation on δ15N and δ13C values of consumers, and the underlying factors that may explain the observed variation. The δ15N and δ13C values were calculated as the differences between the final δ15N and δ13C values of consumers (post-starvation) and the pre-starvation values on each experiment. Our meta-analysis showed a large variation in the δ15N and δ13C values of consumers (δ15N range: -0.82 to 4.30‰; mean: 0.47‰ and δ13C range: -1.92 to 2.62‰; mean: 0.01‰). The δ15N values of most consumers increased along the length of the starvation period and were influenced by nitrogen excretion and thermoregulation types, probably because differences in nitrogen metabolism and thermoregulation affect nitrogen processing and excretion rates. None of our predictor variables accounted for the variation in δ13C values, which showed both increases and decreases due to fasting. Our findings suggest that starvation results in changes in consumer δ15N values which are mainly explained by the length of the fasting period and by nitrogen and energy metabolism, but the underlying mechanisms of the starvation effects on δ13C values seem to be more complex than previously thought.
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Affiliation(s)
- Hideyuki Doi
- Graduate School of Simulation Studies, University of Hyogo, 7-1-28 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
| | - Fumikazu Akamatsu
- National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan
| | - Angélica L. González
- Biology Department and Center for Computational and Integrative Biology, Rutgers University, Camden, NJ, USA
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Keicher L, O'Mara MT, Voigt CC, Dechmann DKN. Stable carbon isotopes in breath reveal fast metabolic incorporation rates and seasonally variable but rapid fat turnover in the common shrew ( Sorex araneus). ACTA ACUST UNITED AC 2017; 220:2834-2841. [PMID: 28546508 DOI: 10.1242/jeb.159947] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 05/21/2017] [Indexed: 11/20/2022]
Abstract
Small non-migratory mammals with Northern distribution ranges apply a variety of behavioural and physiological wintering strategies. A rare energy-saving strategy is Dehnel's phenomenon, involving a reduction and later regrowth of the body size, several organs and parts of the skeleton in red-toothed shrews (Soricidae). The size extremes coincide with major life stages. However, the physiological consequences for the shrew's metabolism remain poorly understood. In keeping with the energetic limitations that may induce the size changes, we hypothesised that metabolic incorporation rates should remain the same across the shrews' lifetimes. In contrast, fat turnover rates should be faster in smaller subadults than in large juveniles and regrown adults, as the metabolic activity of fat tissue increases in winter individuals (subadults). Measuring the changes in the ratio of exhaled stable carbon isotopes, we found that the baseline diet of shrews changed across the season. A diet switch experiment showed that incorporation rates were consistently rapid (t50=38.2±21.1-69.3±53.5 min) and did not change between seasons. As predicted, fat turnover rates were faster in size-reduced subadults (t50=2.1±1.3 h) compared with larger juveniles (t50=5.5±1.7 h) and regrown adults (t50=5.0±4.4 h). In all three age/size classes, all body fat was turned over after 9-24 h. These results show that high levels of nutrient uptake are independent of body size, whereas fat turnover rates are negatively correlated with body size. Thus, the shrews might be under higher pressure to save energy in winter and this may have supported the evolution of Dehnel's phenomenon.
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Affiliation(s)
- Lara Keicher
- Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, 78315 Radolfzell, Germany .,Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - M Teague O'Mara
- Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, 78315 Radolfzell, Germany.,Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - Christian C Voigt
- Evolutionary Ecology Research Group, Leibniz Institute for Zoo and Wildlife Research, 10315 Berlin, Germany
| | - Dina K N Dechmann
- Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, 78315 Radolfzell, Germany.,Department of Biology, University of Konstanz, 78464 Konstanz, Germany
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38
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Asante C, Hobson K, Bond A, Jardine T. Resource partitioning among five species of waterfowl (Anasspp.) at an autumn migratory stopover: combining stable isotope and mercury biomarkers. CAN J ZOOL 2017. [DOI: 10.1139/cjz-2016-0063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Saskatchewan River Delta (SRD) is North America’s largest inland delta and an important stopover site for waterfowl in the Central Flyway. However, little is known about their basic feeding ecology at this site and how species segregate or overlap in resource use. We used stable carbon (δ13C) and nitrogen (δ15N) isotopes and mercury concentrations ([Hg]) in liver tissue to trace use of local nutrient sources by five waterfowl species and tested for differences in diets among species, sexes, and age groups. Macrophytes were the dominant food source for Northern Pintail (Anas acuta L., 1758) and American Wigeon (Anas americana Gmelin, 1789) with median proportions of 0.86 and 0.98, respectively. There was also evidence of partitioning of resources, as Blue-winged Teal (Anas discors L., 1766) and Green-winged Teal (Anas carolinensis Gmelin, 1789) consumed invertebrates, as did a subset of Mallards (Anas platyrhynchos L., 1758), suggesting that these birds might minimize competition for resources during the short staging period in the SRD when waterfowl densities are high. Other isotopes or tracers, such as [Hg] that varied among sources (0.03–0.20 μg·g–1dry mass) and waterfowl species (0.22–3.19 μg·g–1dry mass), can be used for further refining dietary estimates.
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Affiliation(s)
- C.K. Asante
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK S7N 5C8, Canada
| | - K.A. Hobson
- Environment and Climate Change Canada, Saskatoon, SK S7N 3H5, Canada; University of Western Ontario, Department of Biology, London, ON N6A 5B7, Canada
| | - A.L. Bond
- RSPB Centre for Conservation Science, Royal Society for the Protection of Birds, Sandy, Bedfordshire, SG19 2DL, UK; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK S7N 5C8, Canada
| | - T.D. Jardine
- School of Environment and Sustainability, Toxicology Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada
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Pagani-Núñez E, Renom M, Mateos-Gonzalez F, Cotín J, Senar JC. The diet of great tit nestlings: Comparing observation records and stable isotope analyses. Basic Appl Ecol 2017. [DOI: 10.1016/j.baae.2016.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Polito MJ, Brasso RL, Trivelpiece WZ, Karnovsky N, Patterson WP, Emslie SD. Differing foraging strategies influence mercury (Hg) exposure in an Antarctic penguin community. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 218:196-206. [PMID: 27567712 DOI: 10.1016/j.envpol.2016.04.097] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 04/19/2016] [Accepted: 04/29/2016] [Indexed: 06/06/2023]
Abstract
Seabirds are ideal model organisms to track mercury (Hg) through marine food webs as they are long-lived, broadly distributed, and are susceptible to biomagnification due to foraging at relatively high trophic levels. However, using these species as biomonitors requires a solid understanding of the degree of species, sexual and age-specific variation in foraging behaviors which act to mediate their dietary exposure to Hg. We combined stomach content analysis along with Hg and stable isotope analyses of blood, feathers and common prey items to help explain inter and intra-specific patterns of dietary Hg exposure across three sympatric Pygoscelis penguin species commonly used as biomonitors of Hg availability in the Antarctic marine ecosystem. We found that penguin tissue Hg concentrations differed across species, between adults and juveniles, but not between sexes. While all three penguins species diets were dominated by Antarctic krill (Euphausia superba) and to a lesser extent fish, stable isotope based proxies of relative trophic level and krill consumption could not by itself sufficiently explain the observed patterns of inter and intra-specific variation in Hg. However, integrating isotopic approaches with stomach content analysis allowed us to identify the relatively higher risk of Hg exposure for penguins foraging on mesopelagic prey relative to congeners targeting epipelagic or benthic prey species. When possible, future seabird biomonitoring studies should seek to combine isotopic approaches with other, independent measures of foraging behavior to better account for the confounding effects of inter and intra-specific variation on dietary Hg exposure.
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Affiliation(s)
- Michael J Polito
- Louisiana State University, Department of Oceanography and Coastal Sciences, Baton Rouge, LA, 70802, USA.
| | - Rebecka L Brasso
- Southeast Missouri State University, Department of Biology, One University Plaza, MS 6200, Cape Girardeau, MO, 63701, USA
| | - Wayne Z Trivelpiece
- National Marine Fisheries Service, Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, La Jolla, CA, 92037-1508, USA
| | - Nina Karnovsky
- Department of Biology, Pomona College, Claremont, CA, 91711, USA
| | - William P Patterson
- University of Saskatchewan, Department of Geological Sciences, Saskatoon, Saskatchewan, S7N 5E2, Canada
| | - Steven D Emslie
- University of North Carolina Wilmington, Department of Biology and Marine Biology, Wilmington, NC, 28403, USA
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41
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Jaatinen K, Öst M, Hobson KA. State-dependent capital and income breeding: a novel approach to evaluating individual strategies with stable isotopes. Front Zool 2016; 13:24. [PMID: 27284285 PMCID: PMC4899916 DOI: 10.1186/s12983-016-0157-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 05/30/2016] [Indexed: 11/23/2022] Open
Abstract
Background Species-specific strategies for financing the costs of reproduction are well understood, forming a continuum ranging from high to low reliance on stored nutrients. Animals relying mostly on stored reserves are termed ‘capital breeders’, whereas ‘income breeders’ rely mostly on concurrent intake when financing the costs of reproduction. The role and adaptive value of individual variation in these strategies remain elusive. Life-history theory posits that capital breeding should be favoured when offspring reproductive value peaks, typically occurring early in the season, and that current income should increasingly be used with progressing season. Because resource limitation may hamper flexible resource allocation, a corollary prediction is that only good-condition individuals may show the expected seasonal shift in resource use. To test this prediction, we examined stable isotopes (δ13C and δ15N) in blood and lipid-free egg yolk of breeding eider females (Somateria mollissima) from the Baltic Sea to assess the role of individual variation in the use of proteins from local diet vs. stored reserves. Results We show for the first time that individuals from a single population differ in their utilization of stored reserves and concurrent intake to finance the costs of reproduction. Consistent with our prediction, heavy females predominantly used stored reserves for producing egg yolks early in the season, increasingly relying on local feeding with later onset of breeding, whereas light females showed no seasonal change in allocation strategy. Conclusions Stable isotope profiling at the individual level is a powerful tool for monitoring relative changes in investment strategies through time, showing promise as an early warning indicator of ecological change in food webs.
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Affiliation(s)
- Kim Jaatinen
- Novia University of Applied Sciences, Coastal Zone Research Team, Raseborgsvägen 9, FI-10600 Ekenäs, Finland
| | - Markus Öst
- Novia University of Applied Sciences, Coastal Zone Research Team, Raseborgsvägen 9, FI-10600 Ekenäs, Finland ; Environmental and Marine Biology, Faculty of Science and Engineering, Åbo Akademi University, Artillerigatan 6, FI-20520 Turku, Finland
| | - Keith A Hobson
- Environment Canada, 11 Innovation Blvd., Saskatoon, S7N 3H5 Canada ; Department of Biology, University of Western Ontario, 1151 Richmond St., London, ON N6A 5B7 Canada
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Tabak MA, Anderson ORJ, Robb G, Poncet S, Passfield K, Martinez MG, Martinez Del Rio C. Comparative isotopic natural history of two native passerines (
Troglodytes cobbi
and
Cinclodes antarcticus
) and the invasive rats (
Rattus norvegicus
) that extirpate them. AUSTRAL ECOL 2016. [DOI: 10.1111/aec.12351] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Orea R. J. Anderson
- Department of Zoology and Entomology University of Pretoria Pretoria South Africa
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43
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Herrera M. LG, Osorio M. J. Tracking Nutrient Routing in Avian Consumers in a Subtropical Desert. Biotropica 2016. [DOI: 10.1111/btp.12274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- L. Gerardo Herrera M.
- Estación de Biología de Chamela; Instituto de Biología; Universidad Nacional Autónoma de México; Apartado Postal 21 San Patricio Jalisco 48980 Mexico
| | - Jazmín Osorio M.
- Departamento de Ecología y Recursos Naturales; Centro Universitario de la Costa Sur; Universidad de Guadalajara; Av. Independencia Nacional #151 Autlán Jalisco 48900 Mexico
- Facultad de Ciencias Biológicas y Agropecuarias; Autopista Colima-Manzanillo km 40 Crucero de Tecomán; Tecomán Colima 28100 Mexico
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44
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Ceia FR, Ramos JA, Phillips RA, Cherel Y, Jones DC, Vieira RP, Xavier JC. Analysis of stable isotope ratios in blood of tracked wandering albatrosses fails to distinguish a δ(13) C gradient within their winter foraging areas in the southwest Atlantic Ocean. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:2328-2336. [PMID: 26563703 DOI: 10.1002/rcm.7401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/18/2015] [Accepted: 09/19/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE The main limitation of isotopic tracking for inferring distribution is the lack of detailed reference maps of the isotopic landscape (i.e. isoscapes) in the marine environment. Here, we attempt to map the marine δ(13) C isoscape for the southwestern sector of the Atlantic Ocean, and assess any temporal variation using the wandering albatross as a model species. METHODS Tracking data and blood and diet samples were collected monthly from wandering albatrosses rearing chicks at Bird Island, South Georgia, during the austral winter between May and October 2009. The δ(13) C and δ(15) N values were measured by mass spectrometry in plasma and blood cells, and related to highly accurate data on individual movements and feeding activity obtained using three types of device: GPS, activity (immersion) loggers and stomach temperature probes. RESULTS The tracked birds foraged in waters to the north or northwest of South Georgia, including the Patagonian shelf-break, as far as 2000 km from the colony. The foraging region encompassed the two main fronts in the Southern Ocean (Polar and Subantarctic fronts). The δ(13) C values varied by only 2.1 ‰ in plasma and 2.5 ‰ in blood cells, and no relationships were found between the δ(13) C values in plasma and the mean latitude or longitude of landings or feeding events of each individual. CONCLUSIONS The failure to distinguish a major biogeographic gradient in δ(13) C values suggest that these values in the south Atlantic Ocean are fairly homogeneous. There was no substantial variation among months in either the δ(13) C or the δ(15) N values of plasma or blood cells of tracked birds. As birds did not show a significant change in diet composition or foraging areas during the study period, these results provide no evidence for major temporal variation in stable isotope ratios in consumer tissues, or in the regional marine isoscape in the austral winter of 2009.
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Affiliation(s)
- Filipe R Ceia
- MARE - Marine and Environmental Sciences Centre, Department of Life Sciences, Universidade de Coimbra, 3004-517, Coimbra, Portugal
| | - Jaime A Ramos
- MARE - Marine and Environmental Sciences Centre, Department of Life Sciences, Universidade de Coimbra, 3004-517, Coimbra, Portugal
| | - Richard A Phillips
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - Yves Cherel
- Centre d'Etudes Biologiques de Chizé, UPR 7372 du CNRS-Université de La Rochelle, 79360, Villiers-en-Bois, France
| | - Daniel C Jones
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
| | - Rui P Vieira
- MARE - Marine and Environmental Sciences Centre, Department of Life Sciences, Universidade de Coimbra, 3004-517, Coimbra, Portugal
- Departamento de Biologia & CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
- Ocean and Earth Science, National Oceanography Centre, Southampton, European Way, Southampton, SO14 3ZH, UK
| | - José C Xavier
- MARE - Marine and Environmental Sciences Centre, Department of Life Sciences, Universidade de Coimbra, 3004-517, Coimbra, Portugal
- British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
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45
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Newsome SD, Sabat P, Wolf N, Rader JA, del Rio CM. Multi-tissue δ2H analysis reveals altitudinal migration and tissue-specific discrimination patterns inCinclodes. Ecosphere 2015. [DOI: 10.1890/es15-00086.1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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46
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Craig EC, Dorr BS, Hanson-Dorr KC, Sparks JP, Curtis PD. Isotopic Discrimination in the Double-Crested Cormorant (Phalacrocorax auritus). PLoS One 2015; 10:e0140946. [PMID: 26473353 PMCID: PMC4608772 DOI: 10.1371/journal.pone.0140946] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 09/30/2015] [Indexed: 11/18/2022] Open
Abstract
The diet-tissue discrimination factor is the amount by which a consumer’s tissue varies isotopically from its diet, and is therefore a key element in models that use stable isotopes to estimate diet composition. In this study we measured discrimination factors in blood (whole blood, red blood cells and plasma), liver, muscle and feathers of Double-crested Cormorants (Phalacrocorax auritus) for stable isotope ratios of carbon, nitrogen and sulfur. Cormorants exhibited discrimination factors that differed significantly among tissue types (for carbon and nitrogen), and differed substantially (in the context of the isotopic variation among relevant prey species) from those observed in congeneric species. The Double-crested Cormorant has undergone rapid population expansion throughout much of its historic range over the past three decades, leading to both real and perceived conflicts with fisheries throughout North America, and this study provides an essential link for the use of stable isotope analysis in researching foraging ecology, diet, and resource use of this widespread and controversial species.
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Affiliation(s)
- Elizabeth C Craig
- Field of Zoology and Wildlife Conservation, Cornell University, Ithaca, New York, United States of America
| | - Brian S Dorr
- United States Department of Agriculture, Wildlife Services, National Wildlife Research Center, Mississippi Field Station, Mississippi State, Mississippi, United States of America
| | - Katie C Hanson-Dorr
- United States Department of Agriculture, Wildlife Services, National Wildlife Research Center, Mississippi Field Station, Mississippi State, Mississippi, United States of America
| | - Jed P Sparks
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, United States of America
| | - Paul D Curtis
- Department of Natural Resources, Cornell University, Ithaca, New York, United States of America
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47
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Sepúlveda M, Newsome SD, Pavez G, Oliva D, Costa DP, Hückstädt LA. Using Satellite Tracking and Isotopic Information to Characterize the Impact of South American Sea Lions on Salmonid Aquaculture in Southern Chile. PLoS One 2015; 10:e0134926. [PMID: 26309046 PMCID: PMC4550435 DOI: 10.1371/journal.pone.0134926] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 07/15/2015] [Indexed: 11/18/2022] Open
Abstract
Apex marine predators alter their foraging behavior in response to spatial and/or seasonal changes in natural prey distribution and abundance. However, few studies have identified the impacts of aquaculture that represents a spatially and temporally predictable and abundant resource on their foraging behavior. Using satellite telemetry and stable isotope analysis we examined the degree of spatial overlap between the South American sea lion (SASL) and salmon farms, and quantify the amount of native prey versus farmed salmonids in SASL diets. We instrumented eight SASL individuals with SRDL-GPS tags. Vibrissae, hair and skin samples were collected for δ13C and δ15N analyses from five of the tagged individuals and from four males captured in a haul-out located adjacent to salmon farms. Tracking results showed that almost all the foraging areas of SASL are within close proximity to salmon farms. The most important prey for the individuals analyzed was farmed salmonids, with an estimated median (±SD) contribution of 19.7 ± 13.5‰ and 15.3 ± 9.6‰ for hair and skin, respectively. Using vibrissae as a temporal record of diet for each individual, we observed a remarkable switch in diet composition in two SASL, from farmed salmonids to pelagic fishes, which coincided with the decrease of salmon production due to the infectious salmon anemia virus that affected salmon farms in Chile at the end of 2008. Our study demonstrates the usefulness of integrating stable isotope derived dietary data with movement patterns to characterize the impacts of a non-native prey on the foraging ecology of an apex marine predator, providing important applied implications in situations where interactions between aquaculture and wildlife are common.
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Affiliation(s)
- Maritza Sepúlveda
- Centro de Investigación y Gestión de Recursos Naturales (CIGREN), Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Seth D Newsome
- Biology Department, University of New Mexico, Albuquerque, United States of America
| | - Guido Pavez
- Centro de Investigación y Gestión de Recursos Naturales (CIGREN), Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Doris Oliva
- Centro de Investigación y Gestión de Recursos Naturales (CIGREN), Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Daniel P Costa
- University of California Santa Cruz, Ecology and Evolutionary Biology, Santa Cruz, California, United States of America
| | - Luis A Hückstädt
- University of California Santa Cruz, Ecology and Evolutionary Biology, Santa Cruz, California, United States of America
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48
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Carleton SA, Rio CMD, Robinson TJ. Feather isotope analysis reveals differential patterns of habitat and resource use in populations of white-winged doves. J Wildl Manage 2015. [DOI: 10.1002/jwmg.916] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Scott A. Carleton
- US Geological Survey; New Mexico Cooperative Fish and Wildlife Research Unit; Cruces Las NM 88003-8003 USA
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49
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Cloyed CS, Newsome SD, Eason PK. Trophic Discrimination Factors and Incorporation Rates of Carbon- and Nitrogen-Stable Isotopes in Adult Green Frogs, Lithobates clamitans. Physiol Biochem Zool 2015; 88:576-85. [PMID: 26658253 DOI: 10.1086/682576] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Stable isotope analysis is an increasingly useful ecological tool, but its accuracy depends on quantifying the tissue-specific trophic discrimination factors (TDFs) and isotopic incorporation rates for focal taxa. Despite the technique's ubiquity, most laboratory experiments determining TDFs and incorporation rates have focused on birds, mammals, and fish; we know little about terrestrial ectotherms, and amphibians in particular are understudied. In this study we used two controlled feeding experiments to determine carbon (δ(13)C) and nitrogen (δ(15)N) isotope TDFs for skin, whole blood, and bone collagen and incorporation rates for skin and whole blood in adult green frogs, Lithobates clamitans. The mean (±SD) TDFs for δ(13)C were 0.1‰ (±0.4‰) for skin, 0.5‰ (±0.5‰) for whole blood, and 1.6‰ (0.6‰) for bone collagen. The mean (±SD) TDFs for δ(15)N were 2.3‰ (±0.5‰) for skin, 2.3‰ (±0.4‰) for whole blood, and 3.1‰ (±0.6‰) for bone collagen. A combination of different isotopic incorporation models was best supported by our data. Carbon in skin was the only tissue in which incorporation was best explained by two compartments, which had half-lives of 89 and 8 d. The half-life of carbon in whole blood was 69 d. Half-lives for nitrogen were 75 d for skin and 71 d for whole blood. Our results help fill a taxonomic gap in our knowledge of stable isotope dynamics and provide ecologists with a method to measure anuran diets.
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Affiliation(s)
- Carl S Cloyed
- Department of Biology, University of Louisville, Louisville, Kentucky 40292; 2Department of Biology, University of New Mexico, Albuquerque, New Mexico 87131
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50
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Abstract
Diet is a leading modifiable risk factor for chronic disease, but it remains difficult to measure accurately due to the error and bias inherent in self-reported methods of diet assessment. Consequently, there is a pressing need for more objective biomarkers of diet for use in health research. The stable isotope ratios of light elements are a promising set of candidate biomarkers because they vary naturally and reproducibly among foods, and those variations are captured in molecules and tissues with high fidelity. Recent studies have identified valid isotopic measures of short- and long-term sugar intake, meat intake, and fish intake in specific populations. These studies provide a strong foundation for validating stable isotopic biomarkers in the general US population. Approaches to improve specificity for specific foods are needed; for example, by modeling intake using multiple stable isotope ratios or by isolating and measuring specific molecules linked to foods of interest.
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Affiliation(s)
- Diane M O'Brien
- Center for Alaska Native Health Research, Institute of Arctic Biology and Department of Biology and Wildlife, University of Alaska, Fairbanks, Alaska 99775-7000;
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