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Kumar A, Bhardwaj N, Rajaura S, Afzal M, Gupta NJ. Inter-organ differences in redox imbalance and apoptosis depict metabolic resilience in migratory redheaded buntings. Sci Rep 2024; 14:20184. [PMID: 39215166 PMCID: PMC11364690 DOI: 10.1038/s41598-024-71332-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 08/27/2024] [Indexed: 09/04/2024] Open
Abstract
Migration, a bird's metabolic apex, depends primarily on the liver and muscle for fuel mobilization and endurance flight. In migratory redheaded buntings, adaptive increase in mitochondrial membrane (MM) proton gradient to drive ATP synthesis, measured by MM potential (MMP+) and reactive oxygen species (ROS) response, have been well characterized in the blood but not in the muscle or liver. We assessed MMP+, ROS, and apoptosis in the liver and pectoralis muscle of photosensitive nonmigratory (nMig.) male redheaded buntings photoinduced to migratory (Mig.) states. Relative expression levels of genes associated with energy (ACADM, PEPCK, GOT2, GLUT1, and CS), ROS modulation (SIRT1), mitochondrial free-radical scavengers (SOD1, PRX4, NOS2, GPX1, and GPX4), anti-apoptotic genes (NF-κβ), apoptotic (CASP7), and tissue damage using histology, during migration were assessed. The MMP+ decreased and the ROS concentration increased, due to the metabolic load on liver and pectoralis muscle tissues during Mig. However, percentage of apoptotic cells increased in liver but decreased in muscle, which is of functional significance to migratory passerines. During Mig., in muscle, SIRT1 increased, while an increase in anti-apoptotic NF-κβ aided immune pathway-mediated antioxidant activity and guarded against muscle oxidative damage during migration. Inter-organ differences in metabolism add to our current understanding of metabolic flexibility that supports successful migration in buntings.
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Affiliation(s)
- Anit Kumar
- Department of Zoology, Chaudhary Charan Singh University, Meerut, 250004, India
| | - Nitin Bhardwaj
- Department of Zoology and Environmental Science, Gurukula Kangri (Deemed to be University), Haridwar, 249404, India
| | - Sumit Rajaura
- Department of Zoology and Environmental Science, Gurukula Kangri (Deemed to be University), Haridwar, 249404, India
| | - Mohd Afzal
- Department of Chemistry, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia
| | - Neelu Jain Gupta
- Department of Zoology, Chaudhary Charan Singh University, Meerut, 250004, India.
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2
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Carter WA, Pagano SS, Seewagen CL. The effects of diet-shifting from invertebrates towards fruit on the condition of autumn-migrant Catharus thrushes. Oecologia 2024; 204:559-573. [PMID: 38363323 DOI: 10.1007/s00442-024-05511-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 01/08/2024] [Indexed: 02/17/2024]
Abstract
Migration is an energetically challenging and risky life history stage for many animals, but could be supported by dietary choices en route, which may create opportunities to improve body and physiological condition. However, proposed benefits of diet shifts, such as between seasonally available invertebrates and fruits, have received limited investigation in free-living animals. We quantified diet composition and magnitude of autumn diet shifts over two time periods in two closely-related species of migratory songbirds on stopover in the northeastern U.S. (Swainson's thrush [Catharus ustulatus], long-distance migrant, N = 83; hermit thrush [C. guttatus], short-distance migrant, N = 79) and used piecewise structural equation models to evaluate the relationships among (1) migration timing, (2) dietary behavior, and (3) morphometric and physiological condition indices. Tissue isotope composition indicated that both species shifted towards greater fruit consumption. Larger shifts in recent weeks corresponded to higher body condition in Swainson's, but not hermit thrushes, and condition was more heavily influenced by capture date in Swainson's thrushes. Presence of "high-antioxidant" fruits in fecal samples was unrelated to condition in Swainson's thrushes and negatively related to multiple condition indices in hermit thrushes, possibly indicating the value of fruits during migration is related more to their energy and/or macronutrient content than antioxidant content. Our results suggest that increased frugivory during autumn migration can support condition, but those benefits might depend on migration strategy: a longer-distance, more capital-dependent migration strategy could require stricter regulation of body condition aided by increased fruit consumption.
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Affiliation(s)
- Wales A Carter
- Great Hollow Nature Preserve and Ecological Research Center, 225 State Route 37, New Fairfield, CT, 06812, USA.
| | - Susan Smith Pagano
- Thomas H. Gosnell School of Life Sciences, Rochester Institute of Technology, 84 Lomb Memorial Drive, Rochester, NY, 14623, USA
| | - Chad L Seewagen
- Great Hollow Nature Preserve and Ecological Research Center, 225 State Route 37, New Fairfield, CT, 06812, USA
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3
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Ramírez-Otarola N, Maldonado K, Valdés-Ferranty F, Newsome SD, Sabat P. Seasonal changes in diet, immune function, and oxidative stress in three passerines inhabiting a Mediterranean climate. Oecologia 2023; 203:395-405. [PMID: 37950102 DOI: 10.1007/s00442-023-05474-y] [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: 02/25/2023] [Accepted: 10/31/2023] [Indexed: 11/12/2023]
Abstract
Oxidative status and immune function are energy-demanding traits closely linked to diet composition, particularly resource availability and nutritional value. In seasonal environments, nutrient availability and diet quality fluctuate, potentially influencing these traits. However, limited evidence exists regarding these dietary effects on immune function in seasonal environments. In this study, we employed stable isotope analysis to assess the impact of seasonal changes in niche width and trophic level (i.e., δ15N) on two immune variables (hemolysis and hemagglutination scores) and two oxidative status parameters (lipid peroxidation and total antioxidant capacity) in three passerine species: Zonotrichia capensis (omnivorous), Troglodytes aedon (insectivorous), and Spinus barbatus (granivorous). We found that hemolysis scores varied seasonally in Z. capensis, with higher values in winter compared to summer. Total antioxidant capacity (TAC) also increased during the winter in Z. capensis and S. barbatus. The isotopic niche width for Z. capensis and S. barbatus was smaller in winter than in summer, with the omnivorous species exhibiting a decrease in δ15N. Despite the seasonal shifts in ecological and physiological traits in Z. capensis, we identified no correlation between immune response and TAC with trophic level. In contrast, in the granivorous S. barbatus, the lower trophic level resulted in an increase in TAC without affecting immunity. Our findings revealed that dietary shifts do not uniformly impact oxidative status and immune function across bird species, highlighting species-specific responses to seasonal changes. This underscores the importance of integrating ecological and evolutionary perspectives when examining how diet shapes avian immunity and oxidative balance.
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Affiliation(s)
- Natalia Ramírez-Otarola
- Escuela de Medicina Veterinaria, Facultad de Medicina y Ciencias de la Salud, Universidad Mayor, Camino La Pirámide 5750, Huechuraba, Santiago, Chile.
| | - Karin Maldonado
- Departamento de Ciencias, Facultad de Artes Liberales, Universidad Adolfo Ibáñez, Santiago, Chile
| | - Fernanda Valdés-Ferranty
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Seth D Newsome
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
| | - Pablo Sabat
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
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4
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Swanson DL, Stager M, Vézina F, Liu JS, McKechnie AE, Amirkhiz RG. Evidence for a maintenance cost for birds maintaining highly flexible basal, but not summit, metabolic rates. Sci Rep 2023; 13:8968. [PMID: 37268715 DOI: 10.1038/s41598-023-36218-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 05/31/2023] [Indexed: 06/04/2023] Open
Abstract
Reversible phenotypic flexibility allows organisms to better match phenotypes to prevailing environmental conditions and may produce fitness benefits. Costs and constraints of phenotypic flexibility may limit the capacity for flexible responses but are not well understood nor documented. Costs could include expenses associated with maintaining the flexible system or with generating the flexible response. One potential cost of maintaining a flexible system is an energetic cost reflected in the basal metabolic rate (BMR), with elevated BMR in individuals with more flexible metabolic responses. We accessed data from thermal acclimation studies of birds where BMR and/or Msum (maximum cold-induced metabolic rate) were measured before and after acclimation, as a measure of metabolic flexibility, to test the hypothesis that flexibility in BMR (ΔBMR), Msum (ΔMsum), or metabolic scope (Msum - BMR; ΔScope) is positively correlated with BMR. When temperature treatments lasted at least three weeks, three of six species showed significant positive correlations between ΔBMR and BMR, one species showed a significant negative correlation, and two species showed no significant correlation. ΔMsum and BMR were not significantly correlated for any species and ΔScope and BMR were significantly positively correlated for only one species. These data suggest that support costs exist for maintaining high BMR flexibility for some bird species, but high flexibility in Msum or metabolic scope does not generally incur elevated maintenance costs.
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Affiliation(s)
- David L Swanson
- Department of Biology, University of South Dakota, Vermillion, SD, USA.
| | - Maria Stager
- Department of Biology, University of Massachusetts, Amherst, MA, USA
| | - François Vézina
- Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, Rimouski, QC, Canada
| | - Jin-Song Liu
- School of Life and Environmental Sciences, Wenzhou University, Wenzhou, China
| | - Andrew E McKechnie
- DST‑NRF Centre of Excellence at the Percy FitzPatrick Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield, South Africa
- South African Research Chair in Conservation Physiology, South African National Biodiversity Institute, P.O. Box 754, Pretoria, 0001, South Africa
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5
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Voirin CJ, Tsunekage T, Liu Y, Alexy KF, Levin II. Brood size is associated with apparent telomere lengthening in nestling barn swallows. Oecologia 2023; 202:29-40. [PMID: 37087699 DOI: 10.1007/s00442-023-05375-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 04/12/2023] [Indexed: 04/24/2023]
Abstract
Early life for animals is often a time of rapid growth and development. In a resource-limited environment, life history theory predicts that there must be trade-offs between resource sinks in ways that optimize future survival and reproductive success. Telomeres have emerged as putative indicators of these early life trade-offs, but there are conflicting accounts as to how developmental traits and conditions impact telomere length and dynamics. For 2 years, we studied the nestlings of a breeding population of barn swallows from day 6 to day 12 of life, measuring various ontogenetic factors to understand to what extent they explain variation in telomere length and dynamics. We unexpectedly found that telomeres lengthened between the two sampling points. Nestlings in large broods had shorter telomeres, but surprisingly, individuals that grew faster from day 6 to day 12 had longer telomeres and more telomere lengthening. Nestlings with higher mass relative to their nestmates on d6 had shorter telomeres, suggesting that the relatively fast growth barn swallows experience early in development is more costly than the relatively slower growth later in development. These effects were only found in the first year of study. Telomere lengthening may be due to the initiation of new hematopoietic cell lines during development or the expression of telomerase early in life. Favorable early life conditions and high parental investment could allow for more growth with little to no cost to telomere length or dynamics.
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Affiliation(s)
| | - Toshi Tsunekage
- Department of Biology, Kenyon College, Gambier, OH, 43022, USA
| | - Yujie Liu
- Department of Biology, Kenyon College, Gambier, OH, 43022, USA
| | - Kate F Alexy
- Department of Biology, Kenyon College, Gambier, OH, 43022, USA
| | - Iris I Levin
- Department of Biology, Kenyon College, Gambier, OH, 43022, USA
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6
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Salmón P, Millet C, Selman C, Monaghan P, Dawson NJ. Tissue-specific reductions in mitochondrial efficiency and increased ROS release rates during ageing in zebra finches, Taeniopygia guttata. GeroScience 2022; 45:265-276. [PMID: 35986126 PMCID: PMC9886749 DOI: 10.1007/s11357-022-00624-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 07/11/2022] [Indexed: 02/03/2023] Open
Abstract
Mitochondrial dysfunction and oxidative damage have long been suggested as critically important mechanisms underlying the ageing process in animals. However, conflicting data exist on whether this involves increased production of mitochondrial reactive oxygen species (ROS) during ageing. We employed high-resolution respirometry and fluorometry on flight muscle (pectoralis major) and liver mitochondria to simultaneously examine mitochondrial function and ROS (H2O2) release rates in young (3 months) and old (4 years) zebra finches (Taeniopygia guttata). Respiratory capacities for oxidative phosphorylation did not differ between the two age groups in either tissue. Respiratory control ratios (RCR) of liver mitochondria also did not differ between the age classes. However, RCR in muscle mitochondria was 55% lower in old relative to young birds, suggesting that muscle mitochondria in older individuals are less efficient. Interestingly, this observed reduction in muscle RCR was driven almost entirely by higher mitochondrial LEAK-state respiration. Maximum mitochondrial ROS release rates were found to be greater in both flight muscle (1.3-fold) and the liver (1.9-fold) of old birds. However, while maximum ROS (H2O2) release rates from mitochondria increased with age across both liver and muscle tissues, the liver demonstrated a proportionally greater age-related increase in ROS release than muscle. This difference in age-related increases in ROS release rates between muscle and liver tissues may be due to increased mitochondrial leakiness in the muscle, but not the liver, of older birds. This suggests that age-related changes in cellular function seem to occur in a tissue-specific manner in zebra finches, with flight muscle exhibiting signs of minimising age-related increase in ROS release, potentially to reduce damage to this crucial tissue in older individuals.
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Affiliation(s)
- Pablo Salmón
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Graham Kerr Building, Glasgow, G12 8QQ, UK.
| | - Caroline Millet
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Graham Kerr Building, Glasgow, G12 8QQ UK
| | - Colin Selman
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Graham Kerr Building, Glasgow, G12 8QQ UK
| | - Pat Monaghan
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Graham Kerr Building, Glasgow, G12 8QQ UK
| | - Neal J. Dawson
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Graham Kerr Building, Glasgow, G12 8QQ UK
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7
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Viciano J, López-Lázaro S, Tanga C. Post-Mortem Dental Profile as a Powerful Tool in Animal Forensic Investigations—A Review. Animals (Basel) 2022; 12:ani12162038. [PMID: 36009628 PMCID: PMC9404435 DOI: 10.3390/ani12162038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/06/2022] [Accepted: 08/09/2022] [Indexed: 11/16/2022] Open
Abstract
Veterinary forensics is becoming more important in our society as a result of the growing demand for investigations related to crimes against animals or investigations of criminal deaths caused by animals. A veterinarian may participate as an expert witness or may be required to give forensic assistance, by providing knowledge of the specialty to establish a complete picture of the involvement of an animal and allowing the Courts to reach a verdict. By applying diverse dental profiling techniques, not only can species, sex, age-at-death, and body size of an animal be estimated, but also data about their geographical origin (provenance) and the post-mortem interval. This review concentrates on the dental techniques that use the characteristics of teeth as a means of identification of freshly deceased and skeletonised animals. Furthermore, this highlights the information that can be extracted about the animal from the post-mortem dental profile.
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Affiliation(s)
- Joan Viciano
- Department of Medicine and Ageing Sciences, ‘G. d’Annunzio’ University of Chieti-Pescara, 66100 Chieti, Italy
- Correspondence: (J.V.); (S.L.-L.); (C.T.)
| | - Sandra López-Lázaro
- Departamento de Antropología, Facultad de Ciencias Sociales, Universidad de Chile, Santiago 6850331, Chile
- Forensic Dentistry Lab, Centro de Investigación en Odontología Legal y Forense–CIO–, Facultad de Odontología, Universidad de La Frontera, Temuco 4811230, Chile
- Correspondence: (J.V.); (S.L.-L.); (C.T.)
| | - Carmen Tanga
- Department of Legal Medicine, Toxicology and Physical Anthropology, University of Granada, 18016 Granada, Spain
- Correspondence: (J.V.); (S.L.-L.); (C.T.)
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8
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Collett SJ, Crewe TL, Radford IJ, Garnett ST, Campbell HA. Sympatric finches increase trophic and spatiotemporal partitioning to enable coexistence through periods of low resource availability. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sydney J. Collett
- Research Institute for the Environment and Livelihoods Charles Darwin University Darwin NT Australia
| | - Tara L. Crewe
- Research Institute for the Environment and Livelihoods Charles Darwin University Darwin NT Australia
- Department of Lands and Forestry Government of Nova Scotia Kentville NS Canada
| | - Ian J. Radford
- Department of Biodiversity, Conservation and Attractions Biodiversity and Conservation Science WA Australia
| | - Stephen T. Garnett
- Research Institute for the Environment and Livelihoods Charles Darwin University Darwin NT Australia
| | - Hamish A. Campbell
- Research Institute for the Environment and Livelihoods Charles Darwin University Darwin NT Australia
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9
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Guglielmo CG, Morbey YE, Kennedy LV, Deakin JE, Brown JM, Beauchamp AT. A Scaling Approach to Understand the Dynamics of Fat and Lean Mass in Refueling Migrant Songbirds Measured by Quantitative Magnetic Resonance. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.787623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Fat contributes most of the energy for migratory flight of birds, whereas lean body tissues (muscles and organs) contribute amino acids and water to maintain metabolic and osmotic homeostasis. During refueling at stopover sites, both fat and lean mass are recovered, but the dynamics of this recovery are poorly understood. We used non-invasive quantitative magnetic resonance (QMR) analysis to measure fat and lean mass of > 3,500 individuals of 25 songbird species during six spring and three autumn migration seasons between 2009 and 2019 at Long Point, ON, Canada. We used allometric scaling analysis and linear mixed-effects modeling of body composition data at both the population level (single capture) and the individual level (recapture). In the population-level analysis, lean mass scaled hypoallometrically with body mass, such that for every 20% increase in body mass, lean mass was predicted to increase by 12.1% in spring and 12.8% in autumn. Fat scaled hyperallometrically with body mass, such that for every 20% increase in body mass, fat mass was predicted to increase by 144% in spring and 136% in autumn. At the individual level, these allometric relationships were more extreme. As a result of this differential allometry, at low body masses, lean and fat mass contributes nearly equally to changes in mass, but at high body mass fat deposition becomes progressively more dominant. Spring migrants deposited relatively more fat than autumn migrants, and in autumn juvenile birds tended to have greater lean mass than adults. Our findings show that lean mass deposition during refueling by songbirds is substantial, and in line with the losses of protein expected in flight. The process of fat and lean mass deposition is characterized by non-linear dynamics which are influenced by the current body composition, season, and, to a lesser extent, age. The patterns suggest that the need for dietary protein to rebuild lean mass will be greater when body mass is low, during autumn migration, and in juvenile birds.
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10
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Salmón P, Millet C, Selman C, Monaghan P. Growth acceleration results in faster telomere shortening later in life. Proc Biol Sci 2021; 288:20211118. [PMID: 34375555 PMCID: PMC8354743 DOI: 10.1098/rspb.2021.1118] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 07/16/2021] [Indexed: 11/12/2022] Open
Abstract
There is a wealth of evidence for a lifespan penalty when environmental conditions influence an individual's growth trajectory, such that growth rate is accelerated to attain a target size within a limited time period. Given this empirically demonstrated relationship between accelerated growth and lifespan, and the links between lifespan and telomere dynamics, increased telomere loss could underpin this growth-lifespan trade. We experimentally modified the growth trajectory of nestling zebra finches (Taeniopygia guttata), inducing a group of nestlings to accelerate their growth between 7 and 15 days of age, the main phase of body growth. We then sequentially measured their telomere length in red blood cells at various time points from 7 days to full adulthood (120 days). Accelerated growth between 7 and 15 days was not associated with a detectable increase in telomere shortening during this period compared with controls. However, only in the treatment group induced to show growth acceleration was the rate of growth during the experimental period positively related to the amount of telomere shortening between 15 and 120 days. Our findings provide evidence of a long-term influence of growth rate on later-life telomere shortening, but only when individuals have accelerated growth in response to environmental circumstances.
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Affiliation(s)
- Pablo Salmón
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Graham Kerr Building, Glasgow G12 8QQ, UK
| | - Caroline Millet
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Graham Kerr Building, Glasgow G12 8QQ, UK
| | - Colin Selman
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Graham Kerr Building, Glasgow G12 8QQ, UK
| | - Pat Monaghan
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Graham Kerr Building, Glasgow G12 8QQ, UK
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11
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Stanley CQ, Dudash MR, Ryder TB, Gregory Shriver W, Marra PP. Variable tropical moisture and food availability underlie mixed winter space-use strategies in a migratory songbird. Proc Biol Sci 2021; 288:20211220. [PMID: 34284621 PMCID: PMC8292764 DOI: 10.1098/rspb.2021.1220] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 06/30/2021] [Indexed: 11/20/2022] Open
Abstract
Identifying environmental correlates driving space-use strategies can be critical for predicting population dynamics; however, such information can be difficult to attain for small mobile species such as migratory songbirds. We combined radio-telemetry and high-resolution GPS tracking to examine space-use strategies under different moisture gradients for wood thrush (Hylocichla mustelina). We explored the role moisture plays in driving food abundance and, in turn, space-use strategies at a wintering site in Belize across 3 years. Individuals occupying drier habitats experienced lower food abundance and poorer body condition. Using data from our radio-tracked study population and GPS tracking from across five breeding populations, we detected low rates of overwinter site persistence across the wood thrush wintering range. Contrary to expectations, individuals in wetter habitats were more likely to engage in permanent mid-winter relocations, up to 148 km. We suggest facultative movements are instead a condition-dependent strategy that enables wintering wood thrush to locate alternative habitat as food availability declines throughout the dry season. Increased aridity is predicted across the wintering range of wood thrush, and future research should delve deeper into understanding how moisture impacts within and between season space-use dynamics and its ultimate impact on the population dynamics of this declining species.
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Affiliation(s)
- Calandra Q. Stanley
- Migratory Bird Center, Smithsonian Conservation Biology Institute, Washington, DC 20008, USA
- Graduate Program in Behaviour, Ecology, Evolution, and Systematics, University of Maryland, College Park, MD 20742, USA
- Department of Biology and McCourt School of Public Policy, Georgetown University, 37th and O Streets NW, Washington, DC 20057, USA
| | - Michele R. Dudash
- Department of Natural Resource Management, South Dakota State University, Brookings, SD 57007, USA
| | - Thomas B. Ryder
- Migratory Bird Center, Smithsonian Conservation Biology Institute, Washington, DC 20008, USA
- Bird Conservancy of the Rockies, 230 Cherry Street, Suite 150, Fort Collins, CO 80521, USA
| | - W. Gregory Shriver
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE 19716, USA
| | - Peter P. Marra
- Migratory Bird Center, Smithsonian Conservation Biology Institute, Washington, DC 20008, USA
- Department of Biology and McCourt School of Public Policy, Georgetown University, 37th and O Streets NW, Washington, DC 20057, USA
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12
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Morganti M, Polesello S, Pascariello S, Ferrario C, Rubolini D, Valsecchi S, Parolini M. Exposure assessment of PFAS-contaminated sites using avian eggs as a biomonitoring tool: A frame of reference and a case study in the Po River valley (Northern Italy). INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2021; 17:733-745. [PMID: 33764673 DOI: 10.1002/ieam.4417] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/22/2020] [Accepted: 03/23/2021] [Indexed: 06/12/2023]
Abstract
For many years, eggs of diverse bird species have been used as monitoring tools in studies investigating perfluoroalkyl substances (PFAS) contamination, especially in marine and remote areas. Avian eggs are a suitable monitoring matrix because they are relatively easy to collect and their yolks store diverse maternally transferred PFAS. Moreover, the concentrations of PFAS detected in the eggs are a good proxy for maternal exposure and allow the assessment of the potential risk for birds. These features support the use of avian eggs as a key monitoring tool in exposure assessment of PFAS-contaminated sites. We first review the recent application of avian eggs in PFAS monitoring in environmental risk assessment schemes, highlighting strengths and limitations and suggesting which criteria should be considered when selecting a proper study species and structuring the sampling and analytical protocol. Eventually, we report findings from a field study realized in 2020 near a perfluoropolymer factory site in the upper Po plain (Northern Italy), revealing an unprecedented contamination level of PFOA and C6O4 in three species of wild passerines. In future, long-term monitoring of PFAS contamination using avian eggs should be maintained, to provide crucial information on the temporal trend of fluorochemical production and waste disposal, while facilitating early identification of emerging PFAS as well as the quantification of their biomagnification across the trophic web. Integr Environ Assess Manag 2021;17:733-745. © 2021 SETAC.
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Affiliation(s)
- Michelangelo Morganti
- Water Research Institute-National Research Council of Italy, IRSA-CNR, Brugherio, MB, Italy
| | - Stefano Polesello
- Water Research Institute-National Research Council of Italy, IRSA-CNR, Brugherio, MB, Italy
| | - Simona Pascariello
- Water Research Institute-National Research Council of Italy, IRSA-CNR, Brugherio, MB, Italy
| | - Claudia Ferrario
- Water Research Institute-National Research Council of Italy, IRSA-CNR, Brugherio, MB, Italy
| | - Diego Rubolini
- Department of Environmental Science and Policy, University of Milan, Milan, Italy
| | - Sara Valsecchi
- Water Research Institute-National Research Council of Italy, IRSA-CNR, Brugherio, MB, Italy
| | - Marco Parolini
- Department of Environmental Science and Policy, University of Milan, Milan, Italy
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Cooper-Mullin C, Carter WA, Amato RS, Podlesak D, McWilliams SR. Dietary vitamin E reaches the mitochondria in the flight muscle of zebra finches but only if they exercise. PLoS One 2021; 16:e0253264. [PMID: 34181660 PMCID: PMC8238215 DOI: 10.1371/journal.pone.0253264] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 06/01/2021] [Indexed: 01/10/2023] Open
Abstract
Whether dietary antioxidants are effective for alleviating oxidative costs associated with energy-demanding life events first requires they are successfully absorbed in the digestive tract and transported to sites associated with reactive species production (e.g. the mitochondria). Flying birds are under high energy and oxidative demands, and although birds commonly ingest dietary antioxidants in the wild, the bioavailability of these consumed antioxidants is poorly understood. We show for the first time that an ingested lipophilic antioxidant, α-tocopherol, reached the mitochondria in the flight muscles of a songbird but only if they regularly exercise (60 min of perch-to-perch flights two times in a day or 8.5 km day-1). Deuterated α-tocopherol was found in the blood of exercise-trained zebra finches within 6.5 hrs and in isolated mitochondria from pectoral muscle within 22.5 hrs, but never reached the mitochondria in caged sedentary control birds. This rapid pace (within a day) and extent of metabolic routing of a dietary antioxidant to muscle mitochondria means that daily consumption of such dietary sources can help to pay the inevitable oxidative costs of flight muscle metabolism, but only when combined with regular exercise.
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Affiliation(s)
- Clara Cooper-Mullin
- Department of Natural Resources Science, University of Rhode Island, Kingston, Rhode Island, United States of America
| | - Wales A. Carter
- Department of Natural Resources Science, University of Rhode Island, Kingston, Rhode Island, United States of America
| | - Ronald S. Amato
- Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - David Podlesak
- Los Alamos National Laboratory, Los Alamos, New Mexico, United States of America
| | - Scott R. McWilliams
- Department of Natural Resources Science, University of Rhode Island, Kingston, Rhode Island, United States of America
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Whiteman JP, Newsome SD, Bustamante P, Cherel Y, Hobson KA. Quantifying capital versus income breeding: New promise with stable isotope measurements of individual amino acids. J Anim Ecol 2020; 90:1408-1418. [PMID: 33300602 DOI: 10.1111/1365-2656.13402] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 11/09/2020] [Indexed: 11/29/2022]
Abstract
Capital breeders accumulate nutrients prior to egg development, then use these stores to support offspring development. In contrast, income breeders rely on local nutrients consumed contemporaneously with offspring development. Understanding such nutrient allocations is critical to assessing life-history strategies and habitat use. Despite the contrast between these strategies, it remains challenging to trace nutrients from endogenous stores or exogenous food intake into offspring. Here, we tested a new solution to this problem. Using tissue samples collected opportunistically from wild emperor penguins Aptenodytes forsteri, which exemplify capital breeding, we hypothesized that the stable carbon (δ13 C) and nitrogen (δ15 N) isotope values of individual amino acids (AAs) in endogenous stores (e.g. muscle) and in egg yolk and albumen reflect the nutrient sourcing that distinguishes capital versus income breeding. Unlike other methods, this approach does not require untested assumptions or diet sampling. We found that over half of essential AAs had δ13 C values that did not differ between muscle and yolk or albumen, suggesting that most of these AAs were directly routed from muscle into eggs. In contrast, almost all non-essential AAs differed in δ13 C values between muscle and yolk or between muscle and albumen, suggesting de novo synthesis. Over half of AAs that have labile nitrogen atoms (i.e. 'trophic' AA) had higher δ15 N values in yolk and albumen than in muscle, suggesting that they were transaminated during their routing into egg tissue. This effect was smaller for AAs with less labile nitrogen atoms (i.e. 'source' AA). Our results indicate that the δ15 N offset between trophic-source AAs (Δ15 Ntrophic-source ) may provide an index of the extent of capital breeding. The value of emperor penguin Δ15 NPro-Phe was higher in yolk and albumen than in muscle, reflecting the mobilization of endogenous stores; in comparison, the value of Δ15 NPro-Phe was similar across muscle and egg tissue in previously published data for income-breeding herring gulls Larus argentatus smithsonianus. Our results provide a quantitative basis for using AA δ13 C and δ15 N, and isotopic offsets among AAs (e.g. Δ15 NPro-Phe ), to explore the allocation of endogenous versus exogenous nutrients across the capital versus income spectrum of avian reproduction.
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Affiliation(s)
- John P Whiteman
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA.,Department of Biology, University of New Mexico, Albuquerque, NM, USA
| | - Seth D Newsome
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
| | - Paco Bustamante
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 du CNRS-La Rochelle Université, La Rochelle, France
| | - Yves Cherel
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-La Rochelle Université, Villiers-en-Bois, France
| | - Keith A Hobson
- Department of Biology, University of Western Ontario, London, Ontario, Canada.,Environment and Climate Change Canada, Saskatoon, SK, Canada
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15
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Zhao S, Zhang H, Zhang B, Xu Z, Chen A, Zhao Y. A rapid sample preparation method for the analysis of stable isotope ratios of beef samples from different countries. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34:e8795. [PMID: 32220138 DOI: 10.1002/rcm.8795] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/02/2020] [Accepted: 03/25/2020] [Indexed: 06/10/2023]
Abstract
RATIONALE The use of multi-isotopic analyses to trace beef is gaining wider acceptance, but no uniform standard for the pretreatment method is available for the determination of stable isotope ratios. Drying and defatting of meat samples are usually applied. Thus, a rapid sample preparation procedure is required to provide a reference for the study of beef using stable isotope methods. METHODS Student's t-test (T-test) was used to determine significant differences between the δ13 C and δ15 N values in traditional and rapid beef sample preparation methods. The δ13 C, δ15 N, δ2 H, and δ18 O values of beef samples from six countries were assayed using elemental analyzer-isotope ratio mass spectrometry. Stable isotope data were subjected to principal component analysis, discriminant analysis, and partial least-squares discriminant analysis (PLS-DA). RESULTS There was no significant difference (P > 0.05) between the δ13 C and δ15 N values of the two preparation approaches. A classification of satisfactory was obtained with the original-validation rate of 96.6% and the cross-validation rate of 95.9%. The PLS-DA model was correctly validated to differentiate beef samples from six countries. CONCLUSIONS We describe a rapid sample preparation method for beef samples. A model combining stable isotope data and chemometric methods correctly assigned the origin of beef samples from different countries. The results demonstrated the successful utilization of rapid pretreatment methods to prepare beef samples when using multiple stable isotope analyses to trace beef samples from different countries.
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Affiliation(s)
- Shanshan Zhao
- Institute of Quality Standard & Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Agro-Product Quality and Safety, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Hongbo Zhang
- Inner Mongolia Food Safety and Inspection Testing Center, Hohhot, Inner Mongolia, China
| | - Bin Zhang
- College of Food and Bioengineering, Henan University of Science and Technology, Luoyang, China
| | - Zhenzhen Xu
- Institute of Quality Standard & Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Agro-Product Quality and Safety, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Ailiang Chen
- Institute of Quality Standard & Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Agro-Product Quality and Safety, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Yan Zhao
- Institute of Quality Standard & Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Agro-Product Quality and Safety, Ministry of Agriculture and Rural Affairs, Beijing, China
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16
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Malindie S, Buschke F, Codron D. Carbon isotope differences between grassland and savanna herbivores reveal environmentally driven rather than phylogenetically conserved niches. J Zool (1987) 2020. [DOI: 10.1111/jzo.12762] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S. Malindie
- Centre for Environmental Management (IB 67) University of Free State Bloemfontein South Africa
| | - F.T. Buschke
- Centre for Environmental Management (IB 67) University of Free State Bloemfontein South Africa
| | - D. Codron
- Department of Zoology and Entomology (IB 49) University of Free State Bloemfontein South Africa
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17
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McCue MD, Javal M, Clusella‐Trullas S, Le Roux JJ, Jackson MC, Ellis AG, Richardson DM, Valentine AJ, Terblanche JS. Using stable isotope analysis to answer fundamental questions in invasion ecology: Progress and prospects. Methods Ecol Evol 2019. [DOI: 10.1111/2041-210x.13327] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Marshall D. McCue
- Sable Systems International Las Vegas NV USA
- Department of Conservation Ecology and Entomology Centre for Invasion Biology Stellenbosch University Stellenbosch South Africa
| | - Marion Javal
- Department of Conservation Ecology and Entomology Centre for Invasion Biology Stellenbosch University Stellenbosch South Africa
| | - Susana Clusella‐Trullas
- Centre for Invasion Biology Department of Botany and Zoology Stellenbosch University Stellenbosch South Africa
| | - Johannes J. Le Roux
- Centre for Invasion Biology Department of Botany and Zoology Stellenbosch University Stellenbosch South Africa
- Department of Biological Sciences Macquarie University NSW Australia
| | - Michelle C. Jackson
- Centre for Invasion Biology Department of Botany and Zoology Stellenbosch University Stellenbosch South Africa
- Department of Life Sciences Imperial College London Ascot UK
- Department of Zoology Oxford University Oxford UK
| | - Allan G. Ellis
- Department of Botany and Zoology Stellenbosch University Stellenbosch South Africa
| | - David M. Richardson
- Centre for Invasion Biology Department of Botany and Zoology Stellenbosch University Stellenbosch South Africa
| | - Alex J. Valentine
- Department of Botany and Zoology Stellenbosch University Stellenbosch South Africa
| | - John S. Terblanche
- Department of Conservation Ecology and Entomology Centre for Invasion Biology Stellenbosch University Stellenbosch South Africa
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18
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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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19
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Groom DJE, Deakin JE, Lauzau MC, Gerson AR. The role of humidity and metabolic status on lean mass catabolism in migratory Swainson's thrushes (Catharus ustulatus). Proc Biol Sci 2019; 286:20190859. [PMID: 31455196 DOI: 10.1098/rspb.2019.0859] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Migratory birds use protein as a fuel source during flight, but the mechanisms and benefits of protein catabolism during migration are poorly understood. The tissue-specific turnover rate hypothesis proposes that lean mass loss depends solely on the constitutive rate of protein degradation for a given tissue, and is therefore independent of metabolic rate or environmental stimuli. However, it has been demonstrated that environmental stressors such as humidity affect the rate of lean mass catabolism during flight, a finding that seemingly contradicts the tissue-specific turnover rate hypothesis. In order to resolve this, we placed migratory Swainson's thrushes in either high (HEWL) or low (LEWL) evaporative water loss conditions at rest and while undergoing simulated migratory flight at 8 m s-1 in a wind tunnel to test the impact of both environmental stressors and metabolic rate on the rate of protein breakdown. The total quantity and rate of lean mass loss was not different between flight and rest birds, but was affected by humidity condition, with HEWL losing significantly more lean mass. These results show that the rate of protein breakdown in migratory birds is independent of metabolic rate, but it can be augmented in response to environmental stressors.
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Affiliation(s)
- Derrick J E Groom
- Department of Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Jessica E Deakin
- Department of Biology, Western University, London, Ontario, Canada N6A 5B7
| | - M Collette Lauzau
- Department of Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Alexander R Gerson
- Department of Biology, University of Massachusetts Amherst, Amherst, MA 01003, USA
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20
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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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21
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Carter WA, Whiteman JP, Cooper-Mullin C, Newsome SD, McWilliams SR. Dynamics of Individual Fatty Acids in Muscle Fat Stores and Membranes of a Songbird and Its Functional and Ecological Importance. Physiol Biochem Zool 2019; 92:239-251. [PMID: 30741598 DOI: 10.1086/702667] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Although tissue fatty acid (FA) composition has been linked to whole-animal performance (e.g., aerobic endurance, metabolic rate, postexercise recovery) in a wide range of animal taxa, we do not adequately understand the pace of changes in FA composition and its implications for the ecology of animals. Therefore, we used a C4 to C3 diet shift experiment and compound-specific δ13C analysis to estimate the turnover rates of FAs in the polar and neutral fractions of flight muscle lipids (corresponding to membranes and lipid droplets) of exercised and sedentary zebra finches (Taeniopygia guttata). Turnover was fastest for linoleic acid (LA; 18:2n6) and palmitic acid (PA; 16:0), with 95% replacement times of 10.8-17.7 d in the polar fraction and 17.2-32.8 d in the neutral fraction, but was unexpectedly slow for the long-chain polyunsaturated FAs (LC-PUFAs) arachidonic acid (20:4n6) and docosahexaenoic acid (22:6n3) in the polar fraction, with 95% replacement in 64.9-136.5 d. Polar fraction LA and PA turnover was significantly faster in exercised birds (95% replacement in 8.5-13.3 d). Our results suggest that FA turnover in intramuscular lipid droplets is related to FA tissue concentrations and that turnover does not change in response to exercise. In contrast, we found that muscle membrane FA turnover is likely driven by a combination of selective LC-PUFA retention and consumption of shorter-chain FAs in energy metabolism. The unexpectedly fast turnover of membrane-associated FAs in muscle suggests that songbirds during migration could substantially remodel their membranes within a single migration stopover, and this may have substantial implications for how the FA composition of diet affects energy metabolism of birds during migration.
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22
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Quispe R, Yohannes E, Gahr M. Seasonality at the equator: isotope signatures and hormonal correlates of molt phenology in a non-migratory Amazonian songbird. Front Zool 2018; 15:39. [PMID: 30386404 PMCID: PMC6205779 DOI: 10.1186/s12983-018-0284-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 09/25/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Birds, across their annual cycle, progress through sequences of life-history stages such as reproduction and molt. The mechanisms that control annual avian itineraries involve endocrine responses triggered by seasonal environmental factors, including changes in resource availability and/or photoperiod. However, at equatorial latitudes birds are exposed to different degrees of seasonality, and the mechanisms underlying phenology of birds near the equator remain less explored. We studied the silver-beaked tanager, an endemic Amazonian songbird, from an equatorial lowland population. Remarkably, in this species, song behavior has been shown to be seasonally aligned to minimal changes in day length near the equator. Here, we aimed to further explore the phenology of silver-beaked tanagers by assessing shifts of food sources utilization as potential ultimate factors. We measured triple isotopic tracers of carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S) in blood and feathers of birds throughout a whole year. In addition, we assessed the degree of seasonality in the molting activity, in relation to circulating levels of corticosterone, as well as to testosterone as a proxy of the reproductive condition of males. RESULTS There was important seasonal variation of δ34S values in relation to rainfall patterns and changes in estuarine water composition. Despite the seasonal rainfall, we found no substantial variation in the foraging ecology of birds over seasons. This was accompanied by uniform levels of corticosterone throughout the year, probably associated with the absence of drastic seasonal resource shortages. Even so, silver-beaked tanagers showed a marked seasonal molting schedule, which was related to variation in the circulating levels of both corticosterone and testosterone. CONCLUSIONS These findings suggest that foraging niche is not life history stage-dependent in silver-beaked tanagers, and highlight rainfall as an important environmental cue for bird phenology. Our stable isotope results encourage further studies addressing the influence of estuarine water dynamics on bird timing. In addition, the results suggest a primary role of steroid hormones in regulating seasonal life history stages under the absence of a marked photoperiod. Contrary to what might be expected for a tropical songbird, our physiological data in silver-beaked tanagers do not support reproduction-molt overlapping.
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Affiliation(s)
- Rene Quispe
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Strasse, Seewiesen, 82319 Germany
- Present address: Departamento Biología Marina, Facultad Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
| | - Elizabeth Yohannes
- Stable Isotope Lab, Limnological Institute, University of Constance, Konstanz, Germany
| | - Manfred Gahr
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Strasse, Seewiesen, 82319 Germany
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23
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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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Abstract
Migratory birds are physiologically specialized to accumulate massive fat stores (up to 50-60% of body mass), and to transport and oxidize fatty acids at very high rates to sustain flight for many hours or days. Target gene, protein and enzyme analyses and recent -omic studies of bird flight muscles confirm that high capacities for fatty acid uptake, cytosolic transport, and oxidation are consistent features that make fat-fueled migration possible. Augmented circulatory transport by lipoproteins is suggested by field data but has not been experimentally verified. Migratory bats have high aerobic capacity and fatty acid oxidation potential; however, endurance flight fueled by adipose-stored fat has not been demonstrated. Patterns of fattening and expression of muscle fatty acid transporters are inconsistent, and bats may partially fuel migratory flight with ingested nutrients. Changes in energy intake, digestive capacity, liver lipid metabolism and body temperature regulation may contribute to migratory fattening. Although control of appetite is similar in birds and mammals, neuroendocrine mechanisms regulating seasonal changes in fuel store set-points in migrants remain poorly understood. Triacylglycerol of birds and bats contains mostly 16 and 18 carbon fatty acids with variable amounts of 18:2n-6 and 18:3n-3 depending on diet. Unsaturation of fat converges near 70% during migration, and unsaturated fatty acids are preferentially mobilized and oxidized, making them good fuel. Twenty and 22 carbon n-3 and n-6 polyunsaturated fatty acids (PUFA) may affect membrane function and peroxisome proliferator-activated receptor signaling. However, evidence for dietary PUFA as doping agents in migratory birds is equivocal and requires further study.
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Affiliation(s)
- Christopher G Guglielmo
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada N6A5B7
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25
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Schmaljohann H, Eikenaar C. How do energy stores and changes in these affect departure decisions by migratory birds? A critical view on stopover ecology studies and some future perspectives. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 203:411-429. [PMID: 28332031 DOI: 10.1007/s00359-017-1166-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/08/2017] [Accepted: 03/08/2017] [Indexed: 12/01/2022]
Abstract
In birds, accumulating energy is far slower than spending energy during flight. During migration, birds spend, therefore, most of the time at stopover refueling energy used during the previous flight. This elucidates why current energy stores and actual rate of accumulating energy are likely crucial factors influencing bird's decision when to resume migration in addition to other intrinsic (sex, age) and extrinsic (predation, weather) factors modulating the decision within the innate migration program. After first summarizing how energy stores and stopover durations are generally determined, we critically review that high-energy stores and low rates of accumulating energy were significantly related to high departure probabilities in several bird groups. There are, however, also many studies showing no effect at all. Recent radio-tracking studies highlighted that migrants leave a site either to resume migration or to search for a better stopover location, so-called "landscape movements". Erroneously treating such movements as departures increases the likelihood of type II errors which might mistakenly suggest no effect of either trait on departure. Furthermore, we propose that energy loss during the previous migratory flight in relation to bird's current energy stores and migration strategy significantly affects its urge to refuel and hence its departure decision.
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Affiliation(s)
- Heiko Schmaljohann
- Institute of Avian Research "Vogelwarte Helgoland", An der Vogelwarte 21, 26386, Wilhelmshaven, Germany.
| | - Cas Eikenaar
- Institute of Avian Research "Vogelwarte Helgoland", An der Vogelwarte 21, 26386, Wilhelmshaven, Germany
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26
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Basal and maximal metabolic rates differ in their response to rapid temperature change among avian species. J Comp Physiol B 2016; 186:919-35. [DOI: 10.1007/s00360-016-1001-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/22/2016] [Accepted: 05/17/2016] [Indexed: 11/28/2022]
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Mobilization of mercury from lean tissues during simulated migratory fasting in a model songbird. Sci Rep 2016; 6:25762. [PMID: 27173605 PMCID: PMC4865944 DOI: 10.1038/srep25762] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 04/18/2016] [Indexed: 11/08/2022] Open
Abstract
The pollutant methylmercury accumulates within lean tissues of birds and other animals. Migrating birds catabolize substantial amounts of lean tissue during flight which may mobilize methylmercury and increase circulating levels of this neurotoxin. As a model for a migrating songbird, we fasted zebra finches (Taeniopygia guttata) that had been dosed with 0.0, 0.1, and 0.6 parts per million (ppm) dietary methylmercury and measured changes in blood total mercury concentrations (THg) in relation to reductions in lean mass. Birds lost 6–16% of their lean mass during the fast, and THg increased an average of 12% and 11% in the 0.1 and 0.6 ppm treatments, respectively. Trace amounts of THg in the 0.0 ppm control group also increased as a result of fasting, but remained extremely low. THg increased 0.4 ppm for each gram of lean mass catabolized in the higher dose birds. Our findings indicate that methylmercury is mobilized from lean tissues during protein catabolism and results in acute increases in circulating concentrations. This is a previously undocumented potential threat to wild migratory birds, which may experience greater surges in circulating methylmercury than demonstrated here as a result of their greater reductions in lean mass.
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Rode KD, Stricker CA, Erlenbach J, Robbins CT, Cherry SG, Newsome SD, Cutting A, Jensen S, Stenhouse G, Brooks M, Hash A, Nicassio N. Isotopic Incorporation and the Effects of Fasting and Dietary Lipid Content on Isotopic Discrimination in Large Carnivorous Mammals. Physiol Biochem Zool 2016; 89:182-97. [DOI: 10.1086/686490] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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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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Davis M, Pineda Munoz S. The temporal scale of diet and dietary proxies. Ecol Evol 2016; 6:1883-97. [PMID: 27087936 PMCID: PMC4801961 DOI: 10.1002/ece3.2054] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 02/08/2016] [Accepted: 02/12/2016] [Indexed: 11/09/2022] Open
Abstract
Diets estimated from different proxies such as stable isotopes, stomach contents, and dental microwear often disagree, leading to nominally well-supported but greatly differing estimates of diet for both extinct and extant species that complicate our understanding of ecology. We show that these perceived incongruences can be caused by proxies recording diet over vastly different timescales. Field observations reveal a diet averaged over minutes or hours, whereas dental morphology may reflect the diet of a lineage over millions of years of evolution. Failing to explicitly consider the scale of proxies and the potentially large temporal variability in diet can cause erroneous predictions in any downstream analyses such as conservation planning or paleohabitat reconstructions. We propose a cross-scale framework for conceptualizing diet suitable for both modern ecologists and paleontologists and provide recommendations for any studies involving dietary data. Treating diet in this temporally explicit framework and matching the scale of our questions with the scale of our data will lead to a much richer and clearer understanding of ecological and evolutionary processes.
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Affiliation(s)
- Matt Davis
- Department of Geology and Geophysics Yale University New Haven Connecticut 06520; Department of Paleobiology National Museum of Natural History Smithsonian Institution Washington District of Columbia 20004
| | - Silvia Pineda Munoz
- Department of Paleobiology National Museum of Natural History Smithsonian Institution Washington District of Columbia 20004
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McCue MD, Welch KC. (13)C-Breath testing in animals: theory, applications, and future directions. J Comp Physiol B 2015; 186:265-85. [PMID: 26660654 DOI: 10.1007/s00360-015-0950-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/11/2015] [Accepted: 11/25/2015] [Indexed: 10/22/2022]
Abstract
The carbon isotope values in the exhaled breath of an animal mirror the carbon isotope values of the metabolic fuels being oxidized. The measurement of stable carbon isotopes in carbon dioxide is called (13)C-breath testing and offers a minimally invasive method to study substrate oxidation in vivo. (13)C-breath testing has been broadly used to study human exercise, nutrition, and pathologies since the 1970s. Owing to reduced use of radioactive isotopes and the increased convenience and affordability of (13)C-analyzers, the past decade has witnessed a sharp increase in the use of breath testing throughout comparative physiology--especially to answer questions about how and when animals oxidize particular nutrients. Here, we review the practical aspects of (13)C-breath testing and identify the strengths and weaknesses of different methodological approaches including the use of natural abundance versus artificially-enriched (13)C tracers. We critically compare the information that can be obtained using different experimental protocols such as diet-switching versus fuel-switching. We also discuss several factors that should be considered when designing breath testing experiments including extrinsic versus intrinsic (13)C-labelling and different approaches to model nutrient oxidation. We use case studies to highlight the myriad applications of (13)C-breath testing in basic and clinical human studies as well as comparative studies of fuel use, energetics, and carbon turnover in multiple vertebrate and invertebrate groups. Lastly, we call for increased and rigorous use of (13)C-breath testing to explore a variety of new research areas and potentially answer long standing questions related to thermobiology, locomotion, and nutrition.
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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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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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Vander Zanden MJ, Clayton MK, Moody EK, Solomon CT, Weidel BC. Stable isotope turnover and half-life in animal tissues: a literature synthesis. PLoS One 2015; 10:e0116182. [PMID: 25635686 PMCID: PMC4321325 DOI: 10.1371/journal.pone.0116182] [Citation(s) in RCA: 208] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 12/04/2014] [Indexed: 11/27/2022] Open
Abstract
Stable isotopes of carbon, nitrogen, and sulfur are used as ecological tracers for a variety of applications, such as studies of animal migrations, energy sources, and food web pathways. Yet uncertainty relating to the time period integrated by isotopic measurement of animal tissues can confound the interpretation of isotopic data. There have been a large number of experimental isotopic diet shift studies aimed at quantifying animal tissue isotopic turnover rate λ (%·day(-1), often expressed as isotopic half-life, ln(2)/λ, days). Yet no studies have evaluated or summarized the many individual half-life estimates in an effort to both seek broad-scale patterns and characterize the degree of variability. Here, we collect previously published half-life estimates, examine how half-life is related to body size, and test for tissue- and taxa-varying allometric relationships. Half-life generally increases with animal body mass, and is longer in muscle and blood compared to plasma and internal organs. Half-life was longest in ecotherms, followed by mammals, and finally birds. For ectotherms, different taxa-tissue combinations had similar allometric slopes that generally matched predictions of metabolic theory. Half-life for ectotherms can be approximated as: ln (half-life) = 0.22*ln (body mass) + group-specific intercept; n = 261, p<0.0001, r2 = 0.63. For endothermic groups, relationships with body mass were weak and model slopes and intercepts were heterogeneous. While isotopic half-life can be approximated using simple allometric relationships for some taxa and tissue types, there is also a high degree of unexplained variation in our models. Our study highlights several strong and general patterns, though accurate prediction of isotopic half-life from readily available variables such as animal body mass remains elusive.
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Affiliation(s)
- M. Jake Vander Zanden
- Center for Limnology, University of Wisconsin—Madison, Madison,
Wisconsin, United States of America
| | - Murray K. Clayton
- Department of Statistics, University of Wisconsin—Madison, Madison,
Wisconsin, United States of America
| | - Eric K. Moody
- Center for Limnology, University of Wisconsin—Madison, Madison,
Wisconsin, United States of America
- School of Life Sciences, Arizona State University, Tempe, Arizona, United
States of America
| | - Christopher T. Solomon
- Department of Natural Resource Sciences, McGill University, Ste. Anne de
Bellevue, Quebec, Canada
| | - Brian C. Weidel
- Lake Ontario Biological Station, USGS, Oswego, New York, United States of
America
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Thomas SM, Crowther TW. Predicting rates of isotopic turnover across the animal kingdom: a synthesis of existing data. J Anim Ecol 2015; 84:861-870. [DOI: 10.1111/1365-2656.12326] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 11/29/2014] [Indexed: 11/29/2022]
Affiliation(s)
- Stephen M. Thomas
- Department of Environmental Sciences; University of Helsinki; P.O. Box 65 Helsinki FI-00014 Finland
| | - Thomas W. Crowther
- Yale School of Forestry and Environmental Studies; Yale University; 370 Prospect St New Haven CT USA
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Ladin ZS, Williams CK, Castelli PM, Winiarski KJ, Osenkowski J, Mcwilliams SR. Regional and intraseasonal variation in diet of wintering and staging Atlantic brant. J Wildl Manage 2014. [DOI: 10.1002/jwmg.761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Zachary S. Ladin
- Department of Entomology and Wildlife Ecology; University of Delaware; 250 Townsend Hall Newark DE 19716 USA
| | - Christopher K. Williams
- Department of Entomology and Wildlife Ecology; University of Delaware; 253 Townsend Hall Newark DE 19716 USA
| | - Paul M. Castelli
- Research Scientist II Nacote Creek Research Station; New Jersey Division of Fish and Wildlife; P.O. Box 418 Port Republic NJ 08241 USA
| | - Kristopher J. Winiarski
- Department of Natural Resources Science; University of Rhode Island; 105 Coastal Institute in Kingston Kingston RI 02881 USA
| | - Jay Osenkowski
- Rhode Island Department of Environmental Management; Division of Fish and Wildlife; 277 Great Neck Road West Kingston RI 02827 USA
| | - Scott R. Mcwilliams
- Department of Natural Resources Science; University of Rhode Island; 105 Coastal Institute in Kingston Kingston RI 02881 USA
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Kraeer K, Arneson LS, E. MacAvoy S. The intraspecies relationship between tissue turnover and metabolic rate in rats. Ecol Res 2014. [DOI: 10.1007/s11284-014-1182-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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McWilliams SR, Karasov WH. Spare capacity and phenotypic flexibility in the digestive system of a migratory bird: defining the limits of animal design. Proc Biol Sci 2014; 281:20140308. [PMID: 24718764 DOI: 10.1098/rspb.2014.0308] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Flexible phenotypes enable animals to live in environments that change over space and time, and knowing the limits to and the required time scale for this flexibility provides insights into constraints on energy and nutrient intake, diet diversity and niche width. We quantified the level of immediate and ultimate spare capacity, and thus the extent of phenotypic flexibility, in the digestive system of a migratory bird in response to increased energy demand, and identified the digestive constraints responsible for the limits on sustained energy intake. Immediate spare capacity decreased from approximately 50% for birds acclimated to relatively benign temperatures to less than 20% as birds approached their maximum sustainable energy intake. Ultimate spare capacity enabled an increase in feeding rate of approximately 126% as measured in birds acclimated for weeks at -29°C compared with +21°C. Increased gut size and not tissue-specific differences in nutrient uptake or changes in digestive efficiency or retention time were primarily responsible for this increase in capacity with energy demand, and this change required more than 1-2 days. Thus, the pace of change in digestive organ size may often constrain energy intake and, for birds, retard the pace of their migration.
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Affiliation(s)
- Scott R McWilliams
- Department of Forest and Wildlife Ecology, University of Wisconsin, , Madison, WI 53706, USA
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Provencher JF, Braune BM, Gilchrist HG, Forbes MR, Mallory ML. Trace element concentrations and gastrointestinal parasites of Arctic terns breeding in the Canadian High Arctic. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 476-477:308-16. [PMID: 24472719 DOI: 10.1016/j.scitotenv.2014.01.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 01/03/2014] [Accepted: 01/06/2014] [Indexed: 05/24/2023]
Abstract
Baseline data on trace element concentrations are lacking for many species of Arctic marine birds. We measured essential and non-essential element concentrations in Arctic tern (Sterna paradisaea) liver tissue and brain tissue (mercury only) from Canada's High Arctic, and recorded the presence/absence of gastrointestinal parasites during four different phases of the breeding season. Arctic terns from northern Canada had similar trace element concentrations to other seabird species feeding at the same trophic level in the same region. Concentrations of bismuth, selenium, lead and mercury in Arctic terns were high compared to published threshold values for birds. Selenium and mercury concentrations were also higher in Arctic terns from northern Canada than bird species sampled in other Arctic areas. Selenium, mercury and arsenic concentrations varied across the time periods examined, suggesting potential regional differences in the exposure of biota to these elements. For unknown reasons, selenium concentrations were significantly higher in birds with gastrointestinal parasites as compared to those without parasites, while bismuth concentrations were higher in Arctic terns not infected with gastrointestinal parasites.
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Affiliation(s)
- J F Provencher
- Department of Biology, Carleton University, Ottawa, Ontario K1S 5B6, Canada.
| | - B M Braune
- Environment Canada, Science and Technology Branch, Raven Road, Carleton University, Ottawa, Ontario K1S 5 B6, Canada
| | - H G Gilchrist
- Environment Canada, Science and Technology Branch, Raven Road, Carleton University, Ottawa, Ontario K1S 5 B6, Canada
| | - M R Forbes
- Department of Biology, Carleton University, Ottawa, Ontario K1S 5B6, Canada
| | - M L Mallory
- Biology Department, Acadia University, 33 Westwood Avenue, Wolfville, Nova Scotia B4P 2R6, Canada
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Braun A, Auerswald K, Vikari A, Schnyder H. Dietary protein content affects isotopic carbon and nitrogen turnover. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2013; 27:2676-2684. [PMID: 24591029 DOI: 10.1002/rcm.6737] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 08/21/2013] [Accepted: 09/12/2013] [Indexed: 06/03/2023]
Abstract
RATIONALE Isotopic turnover quantifies the metabolic renewal process of elements in organs and excreta. Knowledge of the isotopic turnover of animal organs and excreta is necessary for diet reconstruction via stable isotope analysis, as used in animal ecology, palaeontology and food authentication. Effects of dietary protein content on the isotopic carbon and nitrogen turnover (i.e. delay, representing the time between ingestion and start of renewal, and half-life) are unknown for most mammalian organs and excreta. METHODS To examine the effect of dietary protein content on turnover (delay and turnover rate), we fed 18 rats either a diet at protein maintenance or above protein maintenance, and quantified their isotopic carbon and nitrogen turnover in ten organs and excreta. These included the excreta faeces and urine, the visceral organs blood plasma, liver, kidney, lung and spleen, the cerebral tissue brain, and the muscular tissues heart and muscle. For data analysis, we used piecewise linear/non-linear exponential modelling that allows quantifying delay and turnover rate simultaneously. RESULTS Delays were ~0.5 days for carbon and nitrogen turnover and were not affected by dietary protein content. Half-lives during the following reaction progress were in the range of 1 to 45 days, increasing from excreta to visceral organs to muscular and cerebral organs. Rats fed the higher protein amount had 30% shorter nitrogen half-lives, and 20% shorter carbon half-lives. CONCLUSIONS The renewal times of organs and excreta depend on the dietary protein content. Hence, isotopic diet reconstruction is confronted with variation in half-lives within the same organ or excrement, altering the time window through which information can be perceived.
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Affiliation(s)
- Alexander Braun
- Lehrstuhl für Grünlandlehre, Department of Plant Science, Technische Universität München, D-85350, Freising, Germany
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Caron-Beaudoin É, Gentes ML, Patenaude-Monette M, Hélie JF, Giroux JF, Verreault J. Combined usage of stable isotopes and GPS-based telemetry to understand the feeding ecology of an omnivorous bird, the Ring-billed Gull (Larus delawarensis). CAN J ZOOL 2013. [DOI: 10.1139/cjz-2013-0008] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of the present study was to investigate the feeding ecology of an omnivorous bird, the Ring-billed Gull (Larus delawarensis Ord, 1815), breeding in a highly urbanized and heterogeneous landscape (Montréal area, Quebec, Canada). We used gastrointestinal (G.I.) tract content analysis, GPS-based tracking information, and stable isotope profiles of carbon (δ13C) and nitrogen (δ15N) in selected tissues and major food items. Based on GPS tracking data (1–3 days), Ring-billed Gulls were categorized according to their use of three main foraging habitats: agricultural, St. Lawrence River, and anthropogenic (comprising urban areas, landfills, and wastewater treatment plant basins). Ring-billed Gulls that foraged predominantly in anthropogenic habitats exhibited significantly lower δ15N in blood cells and higher total C to N ratios (C:N) in liver. These lower δ15N and higher C:N ratios were characteristic of profiles determined in food items consumed by Ring-billed Gulls at these urbanized sites (e.g., processed foods). The strong positive correlations between δ13C and δ15N in Ring-billed Gull tissues (plasma, blood cells, and liver) that differed in isotopic turnover times, as well as the strong positive correlations in both δ13C and δ15N between tissue pairs, indicated that Ring-billed Gulls exhibited conserved dietary habits throughout the nesting period. This study demonstrates that combining conventional dietary examination, tissue stable isotope analysis, and fine-scale GPS tracking information may improve our understanding of the large intrapopulation variations in foraging behaviour (and isotopic profiles) commonly observed in omnivorous birds.
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Affiliation(s)
- É. Caron-Beaudoin
- Centre de recherche en toxicologie de l’environnement (TOXEN), Département des sciences biologiques, Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada
| | - M.-L. Gentes
- Centre de recherche en toxicologie de l’environnement (TOXEN), Département des sciences biologiques, Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada
| | - M. Patenaude-Monette
- Groupe de recherche en écologie comportementale et animale (GRECA), Département des sciences biologiques, Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada
| | - J.-F. Hélie
- Centre de recherche en géochimie et géodynamique (GEOTOP), Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada
| | - J.-F. Giroux
- Groupe de recherche en écologie comportementale et animale (GRECA), Département des sciences biologiques, Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada
| | - J. Verreault
- Centre de recherche en toxicologie de l’environnement (TOXEN), Département des sciences biologiques, Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada
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Fraser E, Longstaffe F, Fenton M. Moulting matters: the importance of understanding moulting cycles in bats when using fur for endogenous marker analysis. CAN J ZOOL 2013. [DOI: 10.1139/cjz-2013-0072] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Endogenous markers are a valuable indicator of individual animal ecology, but data interpretation requires a detailed understanding of the timing of tissue formation. Fur is commonly used in bat research using endogenous markers, but the moulting cycles of most bat species are not well documented. In this review, we (i) describe methods of investigating bat moulting; (ii) summarize the current literature on bat moulting cycles, highlighting broad trends; (iii) discuss knowledge gaps; and (iv) make recommendations for optimal fur sampling protocols. Three characteristics may indicate moulting in bats: changing skin pigmentation; visible fur growth and colour changes; and endogenous markers. Most studies reported new fur growth once annually during summer–fall, although there were exceptions. The timing of new fur growth varies among species, sexes, and age classes. Individuals commonly experience asynchronous new fur growth, with dorsal fur growth occurring before ventral. Specific moult progressions vary among species. Knowledge gaps include moulting cycles in tropical species and in subadult and yearling bats; migration during new fur growth; and the timing of fur growth compared with shedding. We recommend that fur samples taken dorsally from adult males are the most likely to be representative of the bat’s site of summer residency.
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Affiliation(s)
- E.E. Fraser
- Environmental Science (Biology), Memorial University of Newfoundland – Grenfell Campus, 20 University Drive, Corner Brook, NL A2H 5G4, Canada
| | - F.J. Longstaffe
- Department of Earth Sciences, The University of Western Ontario, London, ON N6A 5B7, Canada
| | - M.B. Fenton
- Department of Biology, The University of Western Ontario, London, ON N6A 5B7, Canada
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Gerson AR, Guglielmo CG. Measurement of glomerular filtration rate during flight in a migratory bird using a single bolus injection of FITC-inulin. Am J Physiol Renal Physiol 2013; 305:F823-9. [PMID: 23884146 DOI: 10.1152/ajprenal.00247.2013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During migration, passerine birds typically complete a series of multi-hour flights, each followed by a period of stopover. During flight, rates of respiratory water loss are high, yet these birds show no signs of dehydration after flights. During stopover, birds become hyperphagic to replenish fat reserves, often consuming food with high water content, such as fruit. Thus migratory birds seem to face an osmoregulatory challenge; they must reduce water losses during flight but retain the ability to excrete large quantities of water while maintaining osmotic balance at stopover. Our goal was to measure glomerular filtration rate (GFR) and fractional water reabsorption (FWR) of a migratory bird in free flight, at rest, and during feeding to assess the role of the kidney in maintaining water balance during migration. We used FITC-inulin and one- and two-phase exponential decay models to first validate a technique and then measure GFR in the Swainson's thrush, a small (∼30 g) songbird. Single-phase exponential decay models and the modified slope intercept method overestimated GFR by 26% compared with two-phase exponential decay models. We found no differences in GFR among fed, resting and flying birds, but FWR was significantly higher in resting and flying birds relative to feeding birds. There was no effect of the rate of respiratory water loss on GFR or FWR in flight. These data support the idea that birds in flight do not dramatically alter GFR but rely on increased FWR to minimize excretory water losses.
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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.
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Kim SL, del Rio CM, Casper D, Koch PL. Isotopic incorporation rates for shark tissues from a long-term captive feeding study. ACTA ACUST UNITED AC 2012; 215:2495-500. [PMID: 22723489 DOI: 10.1242/jeb.070656] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Stable isotope analysis has provided insight into the dietary and habitat patterns of many birds, mammals and teleost fish. A crucial biological parameter to interpret field stable isotope data is tissue incorporation rate, which has not been well studied in large ectotherms. We report the incorporation of carbon and nitrogen into the tissues of leopard sharks (Triakis semifasciata). Because sharks have relatively slow metabolic rates and are difficult to maintain in captivity, no long-term feeding study has been conducted until the point of isotopic steady state with a diet. We kept six leopard sharks in captivity for 1250 days, measured their growth, and serially sampled plasma, red blood cells and muscle for stable carbon and nitrogen isotope analysis. A single-compartment model with first-order kinetics adequately described the incorporation patterns of carbon and nitrogen isotopes for these three tissues. Both carbon and nitrogen were incorporated faster in plasma than in muscle and red blood cells. The rate of incorporation of carbon into muscle was similar to that predicted by an allometric equation relating isotopic incorporation rate to body mass that was developed previously for teleosts. In spite of their large size and unusual physiology, the rates of isotopic incorporation in sharks seem to follow the same patterns found in other aquatic ectotherms.
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Affiliation(s)
- Sora Lee Kim
- Department of Earth and Planetary Sciences, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA.
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The isotopic composition and insect content of diet predict tissue isotopic values in a South American passerine assemblage. J Comp Physiol B 2012; 183:419-30. [PMID: 23014885 DOI: 10.1007/s00360-012-0711-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 08/30/2012] [Accepted: 08/31/2012] [Indexed: 10/27/2022]
Abstract
We analyzed the carbon and nitrogen isotopic values of the muscle, liver, and crop contents ("diet") of 132 individuals of 16 species of Chilean birds. The nitrogen content of diet was tightly correlated with the fraction of gut contents represented by insects relative to plant material. The carbon and nitrogen isotopic values of diet, liver, and muscle were all linearly correlated, implying high temporal consistency in the isotopic value of the diet of these birds. However, δ(15)N was not significantly related with the percentage of insects in diet. These results cast doubt on the applicability of the use of (15)N enrichment to diagnose trophic level in, at least some, terrestrial ecosystems. However, the residuals of the relationship relating the isotopic value of bird tissues with those of their diet were weakly negatively correlated with insect intake. We hypothesize that this negative correlation stems from the higher quality of protein found in insects relative to that of plant materials. Finally, our data corroborated a perplexing and controversial negative relationship between tissue to diet isotopic discrimination and the isotopic value of diet. We suggest that this relationship is an example of the commonly observed regression to the mean effect that plagues many scientific studies.
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Graves GR, Newsome SD, Willard DE, Grosshuesch DA, Wurzel WW, Fogel ML. Nutritional stress and body condition in the Great Gray Owl (Strix nebulosa) during winter irruptive migrations. CAN J ZOOL 2012. [DOI: 10.1139/z2012-047] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The largest irruptive migration of the Great Gray Owl ( Strix nebulosa Forster, 1772) recorded since 1831 occurred in Minnesota, USA, during the winter of 2004–2005. We tested the hypothesis that morphometric indicators of nutritional stress covary with stable isotope signatures in a sample of 265 owls killed by vehicle collisions. The ratio of carbon to nitrogen in muscle (C/Nmuscle) was shown to be a reliable proxy of nutritional stress. δ13C values for liver and muscle were significantly higher in owls in poor condition, reflecting the depletion of lipid reserves in fasting individuals. On the other hand, δ15N values for liver and muscle were marginally lower or unchanged in owls in poor condition. Stomachs of emaciated owls were less likely to contain prey, implying that many nutritionally stressed individuals were too weak to hunt and were near the tipping point of irreversible fasts. In a broader context, sexual differences in the correlative relationships between stable isotope signatures, C/N, and body condition suggest that the consequences of reversed sexual size dimorphism extend to physiological processes during the nonbreeding season.
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Affiliation(s)
- Gary R. Graves
- Department of Vertebrate Zoology, MRC-116, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, Washington, DC 20013-7012, USA; Center for Macroecology, Evolution and Climate, University of Copenhagen, DK-2100, Copenhagen Ø, Denmark
| | - Seth D. Newsome
- Carnegie Institution of Washington, Geophysical Laboratory, 5251 Broad Branch Road Northwest, Washington, DC 20015, USA; Department of Zoology and Physiology, University of Wyoming, 1000 East University Avenue, Department 3166, Laramie, WY 82071, USA
| | - David E. Willard
- Zoology Department, Field Museum, 1400 South Lake Shore Drive, Chicago, IL 60605-2496, USA
| | | | - William W. Wurzel
- Carnegie Institution of Washington, Geophysical Laboratory, 5251 Broad Branch Road Northwest, Washington, DC 20015, USA; State University of New York College of Environmental Science and Forestry, SUNY-ESF, 1 Forestry Drive, Syracuse, NY 13210, USA
| | - Marilyn L. Fogel
- Carnegie Institution of Washington, Geophysical Laboratory, 5251 Broad Branch Road Northwest, Washington, DC 20015, USA
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Muñoz-Garcia A, Aamidor SE, McCue MD, McWilliams SR, Pinshow B. Allocation of endogenous and dietary protein in the reconstitution of the gastrointestinal tract in migratory blackcaps at stopover sites. ACTA ACUST UNITED AC 2012; 215:1069-75. [PMID: 22399651 DOI: 10.1242/jeb.062547] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
During migratory flight, the mass of the gastrointestinal tract (GIT) and its associated organs in small birds decreases in size by as much as 40%, compared with the preflight condition because of the catabolism of protein. At stopover sites, birds need 2-3 days to rebuild their GIT so that they can restore body mass and fat reserves to continue migration. The source of protein used to rebuild the GIT may be exogenous (from food ingested) or endogenous (reallocated from other organs) or both. Because the relative contribution of these sources to rebuild the GIT of migratory birds is not yet known, we mimicked in-flight fasting and then re-feeding in two groups of blackcaps (Sylvia atricapilla), a Palearctic migratory passerine. The birds were fed a diet containing either 3% or 20% protein to simulate different refueling scenarios. During re-feeding, birds received known doses of (15)N-(l)-leucine before we measured the isotope concentrations in GIT and associated digestive organs and in locomotory muscles. We then quantified the extent to which blackcaps rebuilt their GIT with endogenous and/or dietary protein while refeeding after a fast. Our results indicate that blackcaps fed the low-protein diet incorporated less exogenous nitrogen into their tissues than birds fed the 20% protein diet. They also allocated relatively more exogenous protein to the GIT than to pectoral muscle than those birds re-fed with the high-protein diet. However, this compensation was not sufficient for birds eating the low-protein diet to rebuild their intestine at the same rate as the birds re-fed the high-protein diet. We concluded that blackcaps must choose stopover sites at which they can maximize protein intake to minimize the time it takes to rebuild their GIT and, thus, resume migration as soon as possible.
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Affiliation(s)
- Agustí Muñoz-Garcia
- Mitrani Department of Desert Ecology, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel.
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Lv W, Ju T, Dong B, Yu B, Yin J. Effect of dietary stable isotopic ratios of carbon and nitrogen on the extent of their incorporation into tissues of rats. J Anim Sci Biotechnol 2012; 3:14. [PMID: 22958501 PMCID: PMC3436655 DOI: 10.1186/2049-1891-3-14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Accepted: 05/09/2012] [Indexed: 11/10/2022] Open
Abstract
This study was conducted to investigate the effect of different dietary ratios of 13 C to 12 C or 15 N to 14 N on their relative incorporation into tissues. Eighty male rats were used in two 21-day feeding trials in which they were fed diets with either high δ13C levels (δ13C = −13.89‰ and δ15N = 2.37‰ in experiment 1 and δ13C = −19.34‰ and δ15N = 4.73‰ in experiment 2) or low δ13C levels (δ13C = −17.90‰ and δ15N = 3.08‰ in experiment 1 and δ13C = −21.76‰ and δ15N = 0.53‰ in experiment 2), meanwhile, the dietary δ15N levels were designed to two ranks. Blood, liver, adipose and muscle tissues were collected on day 0, 3, 7, 14, and 21 for determination of 13 C, 12 C, 15 N and 14 N isotopes. Rat growth rate, antioxidant capacity and metabolic parameters were also assessed. The results indicate that adipose tissue tend to deplete 13 C before the stable isotopic ratios achieved final equilibrium. Therefore, feeds with different isotopic signatures had different incorporation rates into tissues. Low dietary 13 C levels decreased tissue δ13C values whereas high dietary 13 C levels did not alter tissue δ13C values during the 21-d experiment. Blood δ15N values were a reliable parameter in assessing the relative contribution of dietary nitrogen to tissues. This study revealed a relationship between dietary isotopic signatures and their incorporation rates into rat tissues. However, more studies are needed to illustrate the mechanism through which dietary isotopic ratios influence the extent of isotopic incorporation into the tissues.
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Affiliation(s)
- Wentao Lv
- State Key Laboratory of Animal Nutrition, China Agricultural University, No,2 West Road Yuanmingyuan, 100193, Beijing, China.
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Martínez del Rio C, Carleton SA. How fast and how faithful: the dynamics of isotopic incorporation into animal tissues: Fig. 1. J Mammal 2012. [DOI: 10.1644/11-mamm-s-165.1] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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