1
|
Ersoy S, Beardsworth CE, Dekinga A, van der Meer MTJ, Piersma T, Groothuis TGG, Bijleveld AI. Exploration speed in captivity predicts foraging tactics and diet in free-living red knots. J Anim Ecol 2021; 91:356-366. [PMID: 34753198 PMCID: PMC9299047 DOI: 10.1111/1365-2656.13632] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 11/01/2021] [Indexed: 11/30/2022]
Abstract
Variation in foraging tactics and diet is usually attributed to differences in morphology, experience and prey availability. Recently, consistent individual differences in behaviour (personality) have been shown to be associated with foraging strategies. Bolder or more exploratory individuals are predicted to have a faster pace-of-life and offset the costs of moving more or in risky areas, with higher energetic gains by encountering profitable foraging opportunities and prey. However, the relationship between personality, foraging and diet is poorly understood. We investigated how exploratory behaviour in red knots Calidris canutus is associated with foraging tactics and diet by combining laboratory experiments, field observations and stable isotope analysis. First, we developed a mobile experimental arena to measure exploration speed in controlled settings. We validated the method by repeated testing of individuals over time and contexts. This setup allowed us to measure exploratory personality at the field site, eliminating the need to bring birds into captivity for long periods of time. After releasing birds within days of their capture, we asked whether exploration speed was associated with differences in foraging tactics and diet in the wild. We found that tactile foraging red knots mainly caught hard-shelled prey that are buried in the sediment, whereas visual foraging knots only captured soft preys located close to or on the surface. We also found that faster explorers showed a higher percentage of visual foraging than slower explorers. By contrast, morphology (bill length and gizzard size) had no significant effect on foraging tactics. Diet analysis based on δ15 N and δ13 C stable isotope values of plasma and red blood cells confirmed our field observations with slower explorers mainly consumed hard-shelled prey while faster explorers consumed more soft than hard-shelled prey. Our results show that foraging tactics and diet are associated with a personality trait, independent of morphological differences. We discuss how consistent behaviour might develop early in life through positive feedbacks between foraging tactics, prey type and foraging efficiency.
Collapse
Affiliation(s)
- Selin Ersoy
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands.,Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, The Netherlands
| | - Christine E Beardsworth
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands
| | - Anne Dekinga
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands
| | - Marcel T J van der Meer
- Department of Marine Microbiology & Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands
| | - Theunis Piersma
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands.,Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, The Netherlands
| | - Ton G G Groothuis
- Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, The Netherlands
| | - Allert I Bijleveld
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands
| |
Collapse
|
2
|
Lei W, Masero JA, Dingle C, Liu Y, Chai Z, Zhu B, Peng H, Zhang Z, Piersma T. The value of coastal saltpans for migratory shorebirds: conservation insights from a stable isotope approach based on feeding guild and body size. Anim Conserv 2021. [DOI: 10.1111/acv.12717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Weipan Lei
- Key Laboratory for Biodiversity Science and Ecological Engineering National Demonstration Center for Experimental Life Sciences & Biotechnology Education College of Life Sciences Beijing Normal University Beijing China
| | - Jose A. Masero
- Ecology in the Anthropocene Associated Unit CSIC‐UEX, Zoology Faculty of Sciences University of Extremadura Badajoz Spain
| | - Caroline Dingle
- Division of Ecology & Biodiversity School of Biological Sciences The University of Hong Kong Hong Kong S.A.R. China
| | - Yang Liu
- State Key Laboratory of Biocontrol School of Ecology School of Life Sciences Sun Yat‐sen University Guangzhou China
| | - Ziwen Chai
- Key Laboratory for Biodiversity Science and Ecological Engineering National Demonstration Center for Experimental Life Sciences & Biotechnology Education College of Life Sciences Beijing Normal University Beijing China
| | - Bingrun Zhu
- Key Laboratory for Biodiversity Science and Ecological Engineering National Demonstration Center for Experimental Life Sciences & Biotechnology Education College of Life Sciences Beijing Normal University Beijing China
- Conservation Ecology Group Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen Groningen The Netherlands
| | - Hebo Peng
- Conservation Ecology Group Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen Groningen The Netherlands
- Department of Coastal Systems NIOZ Royal Netherlands Institute for Sea Research Texel The Netherlands
| | - Zhengwang Zhang
- Key Laboratory for Biodiversity Science and Ecological Engineering National Demonstration Center for Experimental Life Sciences & Biotechnology Education College of Life Sciences Beijing Normal University Beijing China
| | - Theunis Piersma
- Conservation Ecology Group Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen Groningen The Netherlands
- Department of Coastal Systems NIOZ Royal Netherlands Institute for Sea Research Texel The Netherlands
| |
Collapse
|
3
|
Shipley ON, Newton AL, Frisk MG, Henkes GA, LaBelle JS, Camhi MD, Hyatt M, Walters H, Olin JA. Telemetry‐validated nitrogen stable isotope clocks identify ocean‐to‐estuarine habitat shifts in mobile organisms. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13567] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Oliver N. Shipley
- School of Marine and Atmospheric Sciences Stony Brook University Stony Brook NY USA
| | - Alisa L. Newton
- Wildlife Conservation Society, New York Aquarium Brooklyn NY USA
| | - Michael G. Frisk
- School of Marine and Atmospheric Sciences Stony Brook University Stony Brook NY USA
| | | | - Jake S. LaBelle
- Wildlife Conservation Society, New York Aquarium Brooklyn NY USA
| | - Merry D. Camhi
- Wildlife Conservation Society, New York Aquarium Brooklyn NY USA
| | - Michael Hyatt
- Wildlife Conservation Society, New York Aquarium Brooklyn NY USA
| | - Hans Walters
- Wildlife Conservation Society, New York Aquarium Brooklyn NY USA
| | - Jill A. Olin
- Great Lakes Research Center Michigan Technological University Houghton MI USA
| |
Collapse
|
4
|
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.
Collapse
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
| | | |
Collapse
|
5
|
de Necker L, Manfrin A, Ikenaka Y, Ishizuka M, Brendonck L, van Vuren JHJ, Sures B, Wepener V, Smit NJ. Using stable δ13C and δ15N isotopes to assess foodweb structures in an African subtropical temporary pool. AFRICAN ZOOLOGY 2020. [DOI: 10.1080/15627020.2020.1731331] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- L de Necker
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - A Manfrin
- Environmental Campus Birkenfeld, University of Applied Sciences Tier, Standort Umwelt-Campus Birkenfeld, Germany
- Department of Aquatic Ecology and Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany
| | - Y Ikenaka
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - M Ishizuka
- Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - L Brendonck
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
- Animal Ecology, Global Change and Sustainable Development, Department of Biology, University of Leuven, Leuven, Belgium
| | - JHJ van Vuren
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - B Sures
- Department of Aquatic Ecology and Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany
| | - V Wepener
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| | - NJ Smit
- Water Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
| |
Collapse
|
6
|
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
| |
Collapse
|
7
|
Jouta J, Dietz MW, Reneerkens J, Piersma T, Rakhimberdiev E, Hallgrímsson GT, Pen I. Ecological forensics: using single point stable isotope values to infer seasonal schedules of animals after two diet switches. Methods Ecol Evol 2016. [DOI: 10.1111/2041-210x.12695] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Jeltje Jouta
- Department of Coastal Systems and Utrecht University NIOZ Royal Netherlands Institute for Sea Research P.O. Box 59, 1790 AB Den Burg Texel The Netherlands
- Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen P.O. Box 11103 9700 CC Groningen The Netherlands
| | - Maurine W. Dietz
- Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen P.O. Box 11103 9700 CC Groningen The Netherlands
| | - Jeroen Reneerkens
- Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen P.O. Box 11103 9700 CC Groningen The Netherlands
| | - Theunis Piersma
- Department of Coastal Systems and Utrecht University NIOZ Royal Netherlands Institute for Sea Research P.O. Box 59, 1790 AB Den Burg Texel The Netherlands
- Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen P.O. Box 11103 9700 CC Groningen The Netherlands
| | - Eldar Rakhimberdiev
- Department of Coastal Systems and Utrecht University NIOZ Royal Netherlands Institute for Sea Research P.O. Box 59, 1790 AB Den Burg Texel The Netherlands
- Department of Vertebrate Zoology Lomonosov Moscow State University 119991 Moscow Russia
| | | | - Ido Pen
- Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen P.O. Box 11103 9700 CC Groningen The Netherlands
| |
Collapse
|
8
|
van Gils JA, Ahmedou Salem MV. Validating the Incorporation of 13C and 15N in a Shorebird That Consumes an Isotopically Distinct Chemosymbiotic Bivalve. PLoS One 2015; 10:e0140221. [PMID: 26458005 PMCID: PMC4601768 DOI: 10.1371/journal.pone.0140221] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 09/23/2015] [Indexed: 11/18/2022] Open
Abstract
The wealth of field studies using stable isotopes to make inferences about animal diets require controlled validation experiments to make proper interpretations. Despite several pleas in the literature for such experiments, validation studies are still lagging behind, notably in consumers dwelling in chemosynthesis-based ecosystems. In this paper we present such a validation experiment for the incorporation of 13C and 15N in the blood plasma of a medium-sized shorebird, the red knot (Calidris canutus canutus), consuming a chemosymbiotic lucinid bivalve (Loripes lucinalis). Because this bivalve forms a symbiosis with chemoautotrophic sulphide-oxidizing bacteria living inside its gill, the bivalve is isotopically distinct from 'normal' bivalves whose food has a photosynthetic basis. Here we experimentally tested the hypothesis that isotope discrimination and incorporation dynamics are different when consuming such chemosynthesis-based prey. The experiment showed that neither the isotopic discrimination factor, nor isotopic turnover time, differed between birds consuming the chemosymbiotic lucinid and a control group consuming a photosynthesis-based bivalve. This was true for 13C as well as for 15N. However, in both groups the 15N discrimination factor was much higher than expected, which probably had to do with the birds losing body mass over the course of the experiment.
Collapse
Affiliation(s)
- Jan A. van Gils
- NIOZ Royal Netherlands Institute for Sea Research, 1790 AB Den Burg, The Netherlands
- * E-mail:
| | - Mohamed Vall Ahmedou Salem
- EBIOME Ecobiologie Marine et Environnement, Département de Biologie, Université des Sciences, de Technologie et de Médecine, B.P. 880, Nouakchott, Mauritania
- Laboratoire de Biologie Appliquée et Pathologie, Département de Biologie, Faculté des Science, B.P. 2121, Tetouan, Morocco
- Parc National du Banc d’Arguin, B.P. 5355, Nouakchott, Mauritania
| |
Collapse
|
9
|
Phillips DL, Inger R, Bearhop S, Jackson AL, Moore JW, Parnell AC, Semmens BX, Ward EJ. Best practices for use of stable isotope mixing models in food-web studies. CAN J ZOOL 2014. [DOI: 10.1139/cjz-2014-0127] [Citation(s) in RCA: 691] [Impact Index Per Article: 69.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Stable isotope mixing models are increasingly used to quantify consumer diets, but may be misused and misinterpreted. We address major challenges to their effective application. Mixing models have increased rapidly in sophistication. Current models estimate probability distributions of source contributions, have user-friendly interfaces, and incorporate complexities such as variability in isotope signatures, discrimination factors, hierarchical variance structure, covariates, and concentration dependence. For proper implementation of mixing models, we offer the following suggestions. First, mixing models can only be as good as the study and data. Studies should have clear questions, be informed by knowledge of the system, and have strong sampling designs to effectively characterize isotope variability of consumers and resources on proper spatio-temporal scales. Second, studies should use models appropriate for the question and recognize their assumptions and limitations. Decisions about source grouping or incorporation of concentration dependence can influence results. Third, studies should be careful about interpretation of model outputs. Mixing models generally estimate proportions of assimilated resources with substantial uncertainty distributions. Last, common sense, such as graphing data before analyzing, is essential to maximize usefulness of these tools. We hope these suggestions for effective implementation of stable isotope mixing models will aid continued development and application of this field.
Collapse
Affiliation(s)
- Donald L. Phillips
- U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Western Ecology Division, 200 SW 35th Street, Corvallis, OR 97330, USA
| | - Richard Inger
- Environment and Sustainability Institute, School of Biosciences, University of Exeter, Cornwall Campus, Penryn, Cornwall, TR10 9EZ, UK
| | - Stuart Bearhop
- Environment and Sustainability Institute, School of Biosciences, University of Exeter, Cornwall Campus, Penryn, Cornwall, TR10 9EZ, UK
| | - Andrew L. Jackson
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
| | - Jonathan W. Moore
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Andrew C. Parnell
- School of Mathematical Sciences (Statistics), Complex and Adaptive Systems Laboratory, University College Dublin, Dublin 4, Ireland
| | - Brice X. Semmens
- Scripps Institution of Oceanography, University of California – San Diego, San Diego, CA 92093, USA
| | - Eric J. Ward
- Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA 98112, USA
| |
Collapse
|
10
|
Madigan DJ, Baumann Z, Carlisle AB, Hoen DK, Popp BN, Dewar H, Snodgrass OE, Block BA, Fisher NS. Reconstructing transoceanic migration patterns of Pacific bluefin tuna using a chemical tracer toolbox. Ecology 2014; 95:1674-83. [PMID: 25039231 DOI: 10.1890/13-1467.1] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Large pelagic predators play important roles in oceanic ecosystems, and may migrate vast distances to utilize resources in different marine ecoregions. Understanding movement patterns of migratory marine animals is critical for effective management, but often challenging, due to the cryptic habitat of pelagic migrators and the difficulty of assessing past movements. Chemical tracers can partially circumvent these challenges by reconstructing recent migration patterns. Pacific bluefin tuna (Thunnus orientalis; PBFT) inhabit the western and eastern Pacific Ocean, and are in steep decline due to overfishing. Understanding age-specific eastward transpacific migration patterns can improve management practices, but these migratory dynamics remain largely unquantified. Here, we combine a Fukushima-derived radiotracer (134Cs) with bulk tissue and amino acid stable isotope analyses of PBFT to distinguish recent migrants from residents of the eastern Pacific Ocean. The proportion of recent migrants to residents decreased in older year classes, though the proportion of older PBFT that recently migrated across the Pacific was greater than previous estimates. This novel toolbox of biogeochemical tracers can be applied to any species that crosses the North Pacific Ocean.
Collapse
|
11
|
Dietz MW, Piersma T, Dekinga A, Korthals H, Klaassen M. Unusual patterns in ¹⁵N blood values after a diet switch in red knot shorebirds. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2013; 49:283-292. [PMID: 23656233 DOI: 10.1080/10256016.2013.776045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
When a diet switch results in a change in dietary isotopic values, isotope ratios of the consumer's tissues will change until a new equilibrium is reached. This change is generally best described by an exponential decay curve. Indeed, after a diet switch in captive red knot shorebirds (Calidris canutus islandica), the depletion of (13)C in both blood cells and plasma followed an exponential decay curve. Surprisingly, the diet switch with a dietary (15)N/(14)N ratio (δ(15)N) change from 11.4 to 8.8 ‰ had little effect on δ(15)N in the same tissues. The diet-plasma and diet-cellular discrimination factors of (15)N with the initial diet were very low (0.5 and 0.2 ‰, respectively). δ(15)N in blood cells and plasma decreased linearly with increasing body mass, explaining about 40 % of the variation in δ(15)N. δ(15)N in plasma also decreased with increasing body-mass change (r (2)=.07). This suggests that the unusual variation in δ(15)N with time after the diet switch was due to interferences with simultaneous changes in body-protein turnover.
Collapse
Affiliation(s)
- Maurine W Dietz
- Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands.
| | | | | | | | | |
Collapse
|
12
|
Abstract
Stable isotopes can illuminate resource usage by organisms, but effective interpretation is predicated on laboratory validation. Here we develop stable isotope clocks to track resource shifts in anadromous rainbow trout (Oncorhynchus mykiss). We used a diet-switch experiment and model fitting to quantify N stable isotope (δ(15)N) turnover rates and discrimination factors for seven tissues: plasma, liver, fin, mucus, red blood cells, muscle, and scales. Among tissues, diet-tissue δ(15)N discrimination factors ranged from 1.3 to 3.4 ‰. Model-supported tissue turnover half-lives ranged from 9.0 (fin) to 27.7 (scale) days. We evaluated six tissue turnover models using Akaike's information criterion corrected for small sample sizes. The use of equilibrium tissue values was supported in all tissues and two-compartment models were supported in plasma, liver, and mucus. Using parameter estimates and their uncertainty we developed stable isotope clocks to estimate the time since resource shifts. Longer turnover tissues provided accurate estimates of time since resource switch for durations approximately twice their half-life. Faster turnover tissues provided even higher precision estimates, but only within their half-life post-switch. Averaging estimates of time since resource shift from multiple tissues provided the highest precision estimates of time since resource shift for the longest duration (up to 64 days). This study therefore provides insight into physiological processes that underpin stable isotope patterns, explicitly tests alternative models, and quantifies key parameters that are the foundation of field-based stable isotope analysis.
Collapse
|
13
|
Tissue turnover rates and isotopic trophic discrimination factors in the endothermic teleost, pacific bluefin tuna (Thunnus orientalis). PLoS One 2012; 7:e49220. [PMID: 23145128 PMCID: PMC3492276 DOI: 10.1371/journal.pone.0049220] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 10/08/2012] [Indexed: 11/29/2022] Open
Abstract
Stable isotope analysis (SIA) of highly migratory marine pelagic animals can improve understanding of their migratory patterns and trophic ecology. However, accurate interpretation of isotopic analyses relies on knowledge of isotope turnover rates and tissue-diet isotope discrimination factors. Laboratory-derived turnover rates and discrimination factors have been difficult to obtain due to the challenges of maintaining these species in captivity. We conducted a study to determine tissue- (white muscle and liver) and isotope- (nitrogen and carbon) specific turnover rates and trophic discrimination factors (TDFs) using archived tissues from captive Pacific bluefin tuna (PBFT), Thunnus orientalis, 1–2914 days after a diet shift in captivity. Half-life values for 15N turnover in white muscle and liver were 167 and 86 days, and for 13C were 255 and 162 days, respectively. TDFs for white muscle and liver were 1.9 and 1.1‰ for δ15N and 1.8 and 1.2‰ for δ13C, respectively. Our results demonstrate that turnover of 15N and 13C in bluefin tuna tissues is well described by a single compartment first-order kinetics model. We report variability in turnover rates between tissue types and their isotope dynamics, and hypothesize that metabolic processes play a large role in turnover of nitrogen and carbon in PBFT white muscle and liver tissues. 15N in white muscle tissue showed the most predictable change with diet over time, suggesting that white muscle δ15N data may provide the most reliable inferences for diet and migration studies using stable isotopes in wild fish. These results allow more accurate interpretation of field data and dramatically improve our ability to use stable isotope data from wild tunas to better understand their migration patterns and trophic ecology.
Collapse
|
14
|
Wolf N, Newsome SD, Fogel ML, del Rio CM. An experimental exploration of the incorporation of hydrogen isotopes from dietary sources into avian tissues. J Exp Biol 2012; 215:1915-22. [DOI: 10.1242/jeb.065219] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
The analysis of hydrogen stable isotopes (∂D) is a potentially powerful tool for studying animal ecology. Unlike other stable isotopes used in ecological research, however, we are less familiar with the physiological processes that influence the incorporation of hydrogen isotopes from dietary resources to animal tissues. Here we present the results of a controlled feeding experiment utilizing Japanese quail (Cortunix japonica) that was designed to: (1) estimate the relative contributions of diet to the ∂D signatures of blood plasma, red blood cells, intestine, liver, muscle and feathers; (2) investigate possible differences among these same tissues in diet to tissue discrimination; and (3) explore the differences in incorporation dynamics between deuterium (2H) and a well-studied isotope, 13C, for blood plasma solids and red blood cells. Tissues differed in both the relative contribution of diet to tissue ∂D and diet to tissue discrimination. The average residence time of both hydrogen and carbon was significantly lower in plasma solids than in red blood cells. The average residence time of hydrogen was significantly lower than that of carbon in plasma solids, but not in red blood cells. Although the average residence times of hydrogen and carbon were positively correlated, the correlation was weak. Hence the incorporation of carbon seems to be a poor predictor of that of hydrogen.
Collapse
Affiliation(s)
- Nathan Wolf
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA
| | - Seth D. Newsome
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA
| | - Marilyn L. Fogel
- Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA
| | | |
Collapse
|
15
|
Eichhorn G, Meijer HAJ, Oosterbeek K, Klaassen M. Does agricultural food provide a good alternative to a natural diet for body store deposition in geese? Ecosphere 2012. [DOI: 10.1890/es11-00316.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
16
|
Hahn S, Hoye BJ, Korthals H, Klaassen M. From food to offspring down: tissue-specific discrimination and turn-over of stable isotopes in herbivorous waterbirds and other avian foraging guilds. PLoS One 2012; 7:e30242. [PMID: 22312422 PMCID: PMC3270017 DOI: 10.1371/journal.pone.0030242] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2011] [Accepted: 12/16/2011] [Indexed: 11/18/2022] Open
Abstract
Isotopic discrimination and turn-over are fundamental to the application of stable isotope ecology in animals. However, detailed information for specific tissues and species are widely lacking, notably for herbivorous species. We provide details on tissue-specific carbon and nitrogen discrimination and turn-over times from food to blood, feathers, claws, egg tissues and offspring down feathers in four species of herbivorous waterbirds. Source-to-tissue discrimination factors for carbon (δ¹³C) and nitrogen stable isotope ratios (δ¹⁵N) showed little variation across species but varied between tissues. Apparent discrimination factors ranged between -0.5 to 2.5‰ for δ¹³C and 2.8 to 5.2‰ for δ¹⁵N, and were more similar between blood components than between keratinous tissues or egg tissue. Comparing these results with published data from other species we found no effect of foraging guild on discrimination factors for carbon but a significant foraging-guild effect for nitrogen discrimination factors.Turn-over of δ¹³C in tissues was most rapid in blood plasma, with a half-life of 4.3 d, whereas δ¹³C in blood cells had a half-life of approximately 32 d. Turn-over times for albumen and yolk in laying females were similar to those of blood plasma, at 3.2 and 6.0 d respectively. Within yolk, we found decreasing half-life times of δ¹³C from inner yolk (13.3 d) to outer yolk (3.1 d), related to the temporal pattern of tissue formation.We found similarities in tissue-specific turn-over times across all avian species studied to date. Yet, while generalities regarding discrimination factors and tissue turn-over times can be made, a large amount of variation remains unexplained.
Collapse
Affiliation(s)
- Steffen Hahn
- Swiss Ornithological Institute, Sempach, Switzerland.
| | | | | | | |
Collapse
|
17
|
Hoye BJ, Hahn S, Nolet BA, Klaassen M. Habitat use throughout migration: linking individual consistency, prior breeding success and future breeding potential. J Anim Ecol 2012; 81:657-66. [PMID: 22272688 DOI: 10.1111/j.1365-2656.2011.01948.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
1. Habitat use can influence individual performance in a wide range of animals, either immediately or through carry-over effects in subsequent seasons. Given that many animal species also show consistent individual differences in reproductive success, it seems plausible that individuals may have consistent patterns of habitat use representing individual specializations, with concomitant fitness consequences. 2. Stable-carbon isotope ratios from a range of tissues were used to discern individual consistency in habitat use along a terrestrial-aquatic gradient in a long-distance migrant, the Bewick's swan (Cygnus columbianus bewickii). These individual specialisations represented <15% of the isotopic breadth of the population for the majority of individuals and were seen to persist throughout autumn migration and overwintering until aquatic habitats were no longer available. 3. Individual foraging specialisations were then used to demonstrate two consecutive carry-over effects associated with macroscale habitat segregation: consequences of breeding season processes for autumn habitat use; and consequences of autumn habitat use for future reproductive success. Adults that were successful breeders in the year of capture used terrestrial habitats significantly more than adults that were not successful, revealing a substantial cost of reproduction and extended parental care. Use of aquatic habitats during autumn was, however, associated with increased body condition prior to spring migration; and increased subsequent breeding success in adults that had been unsuccessful the year before. Yet adults that were successful breeders in the year of capture remained the most likely to be successful the following year, despite their use of terrestrial habitats. 4. Our results uniquely demonstrate not only individual foraging specializations throughout the migration period, but also that processes during breeding and autumn migration, mediated by individual consistency, may play a fundamental role in the population dynamics of long-distance migrants. These findings, therefore, highlight the importance of long-term consistency to our understanding of habitat function, interindividual differences in fitness, population dynamics and the evolution of migratory strategies.
Collapse
Affiliation(s)
- Bethany J Hoye
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB Wageningen, The Netherlands.
| | | | | | | |
Collapse
|
18
|
Boecklen WJ, Yarnes CT, Cook BA, James AC. On the Use of Stable Isotopes in Trophic Ecology. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2011. [DOI: 10.1146/annurev-ecolsys-102209-144726] [Citation(s) in RCA: 623] [Impact Index Per Article: 47.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- William J. Boecklen
- Laboratory of Ecological Chemistry, Department of Biology, New Mexico State University, Las Cruces, New Mexico 88003; , ,
| | - Christopher T. Yarnes
- Stable Isotope Facility, Department of Plant Sciences, University of California, Davis, Davis, California 95616;
| | - Bethany A. Cook
- Laboratory of Ecological Chemistry, Department of Biology, New Mexico State University, Las Cruces, New Mexico 88003; , ,
| | - Avis C. James
- Laboratory of Ecological Chemistry, Department of Biology, New Mexico State University, Las Cruces, New Mexico 88003; , ,
| |
Collapse
|
19
|
Hoye BJ. Variation in postsampling treatment of avian blood affects ecophysiological interpretations. Methods Ecol Evol 2011. [DOI: 10.1111/j.2041-210x.2011.00135.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
20
|
Lecomte N, Ahlstrøm O, Ehrich D, Fuglei E, Ims RA, Yoccoz NG. Intrapopulation variability shaping isotope discrimination and turnover: experimental evidence in arctic foxes. PLoS One 2011; 6:e21357. [PMID: 21731715 PMCID: PMC3121787 DOI: 10.1371/journal.pone.0021357] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 05/31/2011] [Indexed: 11/23/2022] Open
Abstract
Background Tissue-specific stable isotope signatures can provide insights into the trophic ecology of consumers and their roles in food webs. Two parameters are central for making valid inferences based on stable isotopes, isotopic discrimination (difference in isotopic ratio between consumer and its diet) and turnover time (renewal process of molecules in a given tissue usually measured when half of the tissue composition has changed). We investigated simultaneously the effects of age, sex, and diet types on the variation of discrimination and half-life in nitrogen and carbon stable isotopes (δ15N and δ13C, respectively) in five tissues (blood cells, plasma, muscle, liver, nail, and hair) of a top predator, the arctic fox Vulpes lagopus. Methodology/Principal Findings We fed 40 farmed foxes (equal numbers of adults and yearlings of both sexes) with diet capturing the range of resources used by their wild counterparts. We found that, for a single species, six tissues, and three diet types, the range of discrimination values can be almost as large as what is known at the scale of the whole mammalian or avian class. Discrimination varied depending on sex, age, tissue, and diet types, ranging from 0.3‰ to 5.3‰ (mean = 2.6‰) for δ15N and from 0.2‰ to 2.9‰ (mean = 0.9‰) for δ13C. We also found an impact of population structure on δ15N half-life in blood cells. Varying across individuals, δ15N half-life in plasma (6 to 10 days) was also shorter than for δ13C (14 to 22 days), though δ15N and δ13C half-lives are usually considered as equal. Conclusion/Significance Overall, our multi-factorial experiment revealed that at least six levels of isotopic variations could co-occur in the same population. Our experimental analysis provides a framework for quantifying multiple sources of variation in isotopic discrimination and half-life that needs to be taken into account when designing and analysing ecological field studies.
Collapse
Affiliation(s)
- Nicolas Lecomte
- Department of Arctic and Marine Biology, University of Tromsø, Tromsø, Norway.
| | | | | | | | | | | |
Collapse
|