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Beltran RS, Lozano RR, Morris PA, Robinson PW, Holser RR, Keates TR, Favilla AB, Kilpatrick AM, Costa DP. Individual variation in life-history timing: synchronous presence, asynchronous events and phenological compensation in a wild mammal. Proc Biol Sci 2024; 291:20232335. [PMID: 38628129 PMCID: PMC11021928 DOI: 10.1098/rspb.2023.2335] [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: 10/15/2023] [Accepted: 03/14/2024] [Indexed: 04/19/2024] Open
Abstract
Many animals and plants have species-typical annual cycles, but individuals vary in their timing of life-history events. Individual variation in fur replacement (moult) timing is poorly understood in mammals due to the challenge of repeated observations and longitudinal sampling. We examined factors that influence variation in moult duration and timing among elephant seals (Mirounga angustirostris). We quantified the onset and progression of fur loss in 1178 individuals. We found that an exceptionally rapid visible moult (7 days, the shortest of any mammals or birds), and a wide range of moult start dates (spanning 6-10× the event duration) facilitated high asynchrony across individuals (only 20% of individuals in the population moulting at the same time). Some of the variation was due to reproductive state, as reproductively mature females that skipped a breeding season moulted a week earlier than reproductive females. Moreover, individual variation in timing and duration within age-sex categories far outweighed (76-80%) variation among age-sex categories. Individuals arriving at the end of the moult season spent 50% less time on the beach, which allowed them to catch up in their annual cycles and reduce population-level variance during breeding. These findings underscore the importance of individual variation in annual cycles.
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Affiliation(s)
- Roxanne S. Beltran
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Raquel R. Lozano
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Patricia A. Morris
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Patrick W. Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Rachel R. Holser
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Theresa R. Keates
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Arina B. Favilla
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - A. Marm Kilpatrick
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Daniel P. Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95060, USA
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA 95060, USA
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2
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Hoelzel AR, Gkafas GA, Kang H, Sarigol F, Le Boeuf B, Costa DP, Beltran RS, Reiter J, Robinson PW, McInerney N, Seim I, Sun S, Fan G, Li S. Genomics of post-bottleneck recovery in the northern elephant seal. Nat Ecol Evol 2024; 8:686-694. [PMID: 38383849 PMCID: PMC11009102 DOI: 10.1038/s41559-024-02337-4] [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: 06/29/2023] [Accepted: 01/19/2024] [Indexed: 02/23/2024]
Abstract
Populations and species are threatened by human pressure, but their fate is variable. Some depleted populations, such as that of the northern elephant seal (Mirounga angustirostris), recover rapidly even when the surviving population was small. The northern elephant seal was hunted extensively and taken by collectors between the early 1800s and 1892, suffering an extreme population bottleneck as a consequence. Recovery was rapid and now there are over 200,000 individuals. We sequenced 260 modern and 8 historical northern elephant seal nuclear genomes to assess the impact of the population bottleneck on individual northern elephant seals and to better understand their recovery. Here we show that inbreeding, an increase in the frequency of alleles compromised by lost function, and allele frequency distortion, reduced the fitness of breeding males and females, as well as the performance of adult females on foraging migrations. We provide a detailed investigation of the impact of a severe bottleneck on fitness at the genomic level and report on the role of specific gene systems.
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Affiliation(s)
| | - Georgios A Gkafas
- Department of Ichthyology and Aquatic Environment, University of Thessaly, Volos, Greece
| | - Hui Kang
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- Innovation Research Center for Aquatic Mammals, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | | | - Burney Le Boeuf
- Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Daniel P Costa
- Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Roxanne S Beltran
- Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Joanne Reiter
- Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Patrick W Robinson
- Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Nancy McInerney
- Center for Conservation Genomics, National Zoo and Conservation Biology Institute, Smithsonian Institution, Washington, DC, USA
| | - Inge Seim
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China
- Integrative Biology Laboratory, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | | | | | - Songhai Li
- Marine Mammal and Marine Bioacoustics Laboratory, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya, China.
- Innovation Research Center for Aquatic Mammals, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.
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3
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Hernández CM, Ellner SP, Snyder RE, Hooker G. The natural history of luck: A synthesis study of structured population models. Ecol Lett 2024; 27:e14390. [PMID: 38549267 DOI: 10.1111/ele.14390] [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: 07/31/2023] [Revised: 01/18/2024] [Accepted: 02/08/2024] [Indexed: 04/02/2024]
Abstract
Chance pervades life. In turn, life histories are described by probabilities (e.g. survival and breeding) and averages across individuals (e.g. mean growth rate and age at maturity). In this study, we explored patterns of luck in lifetime outcomes by analysing structured population models for a wide array of plant and animal species. We calculated four response variables: variance and skewness in both lifespan and lifetime reproductive output (LRO), and partitioned them into contributions from different forms of luck. We examined relationships among response variables and a variety of life history traits. We found that variance in lifespan and variance in LRO were positively correlated across taxa, but that variance and skewness were negatively correlated for both lifespan and LRO. The most important life history trait was longevity, which shaped variance and skew in LRO through its effects on variance in lifespan. We found that luck in survival, growth, and fecundity all contributed to variance in LRO, but skew in LRO was overwhelmingly due to survival luck. Rapidly growing populations have larger variances in LRO and lifespan than shrinking populations. Our results indicate that luck-induced genetic drift may be most severe in recovering populations of species with long mature lifespan and high iteroparity.
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Affiliation(s)
- Christina M Hernández
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Stephen P Ellner
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA
| | - Robin E Snyder
- Department of Biology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Giles Hooker
- Department of Statistics and Data Science, Cornell University, Ithaca, New York, USA
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4
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Peterson SH, Peterson MG, Ackerman JT, Debier C, Goetsch C, Holser RR, Hückstädt LA, Johnson JC, Keates TR, McDonald BI, McHuron EA, Costa DP. Foraging behavior and age affect maternal transfer of mercury to northern elephant seal pups. Sci Rep 2024; 14:4693. [PMID: 38409311 PMCID: PMC10897339 DOI: 10.1038/s41598-024-54527-6] [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: 09/22/2023] [Accepted: 02/13/2024] [Indexed: 02/28/2024] Open
Abstract
Deep ocean foraging northern elephant seals (Mirounga angustirostris) consume fish and squid in remote depths of the North Pacific Ocean. Contaminants bioaccumulated from prey are subsequently transferred by adult females to pups during gestation and lactation, linking pups to mercury contamination in mesopelagic food webs (200-1000 m depths). Maternal transfer of mercury to developing seal pups was related to maternal mercury contamination and was strongly correlated with maternal foraging behavior (biotelemetry and isotopes). Mercury concentrations in lanugo (hair grown in utero) were among the highest observed worldwide for young pinnipeds (geometric mean 23.01 μg/g dw, range 8.03-63.09 μg/g dw; n = 373); thus, some pups may be at an elevated risk of sub-lethal adverse health effects. Fetal mercury exposure was affected by maternal foraging geographic location and depth; mercury concentrations were highest in pups of the deepest diving, pelagic females. Moreover, pup lanugo mercury concentrations were strongly repeatable among successive pups of individual females, demonstrating relative consistency in pup mercury exposure based on maternal foraging strategies. Northern elephant seals are biosentinels of a remote deep-sea ecosystem. Our results suggest that mercury within North Pacific mesopelagic food webs may also pose an elevated risk to other mesopelagic-foraging predators and their offspring.
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Affiliation(s)
- Sarah H Peterson
- Western Ecological Research Center, Dixon Field Station, U.S. Geological Survey, 800 Business Park Drive Suite D, Dixon, CA, USA.
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA.
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA.
| | - Michael G Peterson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Joshua T Ackerman
- Western Ecological Research Center, Dixon Field Station, U.S. Geological Survey, 800 Business Park Drive Suite D, Dixon, CA, USA
| | - Cathy Debier
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Chandra Goetsch
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
- CSS, Inc, Fairfax, VA, USA
| | - Rachel R Holser
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Luis A Hückstädt
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
| | - Jennifer C Johnson
- Moss Landing Marine Labs, San Jose State University, Moss Landing, CA, USA
| | - Theresa R Keates
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | | | - Elizabeth A McHuron
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Daniel P Costa
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
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5
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Condit R, Hatfield B, Morris PA, Costa DP. Quantifying dispersal between two colonies of northern elephant seals across 17 birth cohorts. PLoS One 2023; 18:e0288921. [PMID: 38032885 PMCID: PMC10688689 DOI: 10.1371/journal.pone.0288921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 07/06/2023] [Indexed: 12/02/2023] Open
Abstract
Dispersal drives extinction-recolonization dynamics of metapopulations and is necessary for endangered species to recolonize former ranges. Yet few studies quantify dispersal and even fewer examine consistency of dispersal over many years. The northern elephant seal (Mirounga angustirostris) provides an example of the importance of dispersal. It quickly recolonized its full range after near extirpation by 19th century hunting, and though dispersal was observed it was not quantified. Here we enumerate lifetime dispersal events among females marked as pups at two colonies during 1994-2010, then correct for detection biases to estimate bidirectional dispersal rates. An average of 16% of females born at the Piedras Blancas colony dispersed northward 200 km to breed at Año Nuevo, while 8.0% of those born at Año Nuevo dispersed southward to Piedras Blancas. The northward rate fluctuated considerably but was higher than southward in 15 of 17 cohorts. The population at Piedras Blancas expanded 15-fold during the study, while Año Nuevo's declined slightly, but the expectation that seals would emigrate away from high density colonies was not supported. During the 1990s, dispersal was higher away from the small colony toward the large. Moreover, cohorts born later at Piedras Blancas, when the colony had grown, dispersed no more than early cohorts. Consistently high natal dispersal in northern elephant seals means the population must be considered a single large unit in terms of response to environmental change. High dispersal was fortuitous to the past recovery of the species, and continued dispersal means elephant seals will likely expand their range further.
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Affiliation(s)
- Richard Condit
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, United States of America
| | | | - Patricia A. Morris
- Institute for Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA, United States of America
| | - Daniel P. Costa
- Institute for Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA, United States of America
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6
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Hastings KK, Jemison LA, Pendleton GW, Johnson DS, Gelatt TS. Age-specific reproduction in female Steller sea lions in Southeast Alaska. Ecol Evol 2023; 13:e10515. [PMID: 37780535 PMCID: PMC10533480 DOI: 10.1002/ece3.10515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 08/04/2023] [Accepted: 08/23/2023] [Indexed: 10/03/2023] Open
Abstract
Age-, region-, and year-specific estimates of reproduction are needed for monitoring wildlife populations during periods of ecosystem change. Population dynamics of Steller sea lions (Eumetopias jubatus) in Southeast Alaska varied regionally (with high population growth and survival in the north vs. the south) and annually (with reduced adult female survival observed following a severe marine heatwave event), but reproductive performance is currently unknown. We used mark-resighting data from 1006 Steller sea lion females marked as pups at ~3 weeks of age from 1994 to 1995 and from 2001 to 2005 and resighted from 2002 to 2019 (to a maximum age of 25) to examine age-, region-, and year-specific reproduction. In the north versus the south, age of first reproduction was earlier (beginning at age 4 vs. age 5, respectively) but annual birth probabilities of parous females were reduced by 0.05. In an average year pre-heatwave, the proportion of females with pup at the end of the pupping season peaked at ages 12-13 with ~0.60/0.65 (north/south) with pup, ~0.30/0.25 with juvenile, and ~0.10 (both regions) without a dependent. In both regions, reproductive senescence was gradual after age 12: ~0.40, 0.40, and 0.20 of females were in these reproductive states, respectively, by age 20. Correcting for neonatal mortality, true birth probabilities at peak ages were 0.66/0.72 (north/south). No cost of reproduction on female survival was detected, but pup production remained lower (-0.06) after the heatwave event, which if sustained could result in population decline in the south. Reduced pup production and greater retention of juveniles during periods of poor prey conditions may be an important strategy for Steller sea lions in Southeast Alaska, where fine-tuning reproduction based on nutritional status may improve the lifetime probability of producing pups under good conditions in a variable and less productive environment.
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Affiliation(s)
| | | | | | - Devin S. Johnson
- Protected Resources Division, National Marine Fisheries ServicePacific Islands Fisheries Science CenterHonoluluHawaiiUSA
| | - Thomas S. Gelatt
- Marine Mammal Laboratory, National Marine Fisheries ServiceAlaska Fisheries Science CenterSeattleWashingtonUSA
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7
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Mott R, Prowse TAA, Jackson MV, Rogers DJ, O'Connor JA, Brookes JD, Cassey P. Measuring habitat quality for waterbirds: A review. Ecol Evol 2023; 13:e9905. [PMID: 37038530 PMCID: PMC10082184 DOI: 10.1002/ece3.9905] [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: 12/07/2021] [Revised: 12/30/2022] [Accepted: 02/28/2023] [Indexed: 04/12/2023] Open
Abstract
Quantifying habitat quality is dependent on measuring a site's relative contribution to population growth rate. This is challenging for studies of waterbirds, whose high mobility can decouple demographic rates from local habitat conditions and make sustained monitoring of individuals near-impossible. To overcome these challenges, biologists have used many direct and indirect proxies of waterbird habitat quality. However, consensus on what methods are most appropriate for a given scenario is lacking. We undertook a structured literature review of the methods used to quantify waterbird habitat quality, and provide a synthesis of the context-dependent strengths and limitations of those methods. Our search of the Web of Science and Scopus databases returned a sample of 666 studies, upon which our review was based. The reviewed studies assessed habitat quality by either measuring habitat attributes (e.g., food abundance, water quality, vegetation structure), or measuring attributes of the waterbirds themselves (e.g., demographic parameters, body condition, behavior, distribution). Measuring habitat attributes, although they are only indirectly related to demographic rates, has the advantage of being unaffected by waterbird behavioral stochasticity. Conversely, waterbird-derived measures (e.g., body condition, peck rates) may be more directly related to demographic rates than habitat variables, but may be subject to greater stochastic variation (e.g., behavioral change due to presence of conspecifics). Therefore, caution is needed to ensure that the measured variable does influence waterbird demographic rates. This assumption was usually based on ecological theory rather than empirical evidence. Our review highlighted that there is no single best, universally applicable method to quantify waterbird habitat quality. Individual project specifics (e.g., time frame, spatial scale, funding) will influence the choice of variables measured. Where possible, practitioners should measure variables most directly related to demographic rates. Generally, measuring multiple variables yields a better chance of accurately capturing the relationship between habitat characteristics and demographic rates.
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Affiliation(s)
- Rowan Mott
- School of Biological SciencesThe University of AdelaideAdelaideSouth AustraliaAustralia
| | - Thomas A. A. Prowse
- School of Biological SciencesThe University of AdelaideAdelaideSouth AustraliaAustralia
| | - Micha V. Jackson
- School of Biological SciencesThe University of AdelaideAdelaideSouth AustraliaAustralia
| | - Daniel J. Rogers
- School of Biological SciencesThe University of AdelaideAdelaideSouth AustraliaAustralia
- Department for Environment and WaterAdelaideSouth AustraliaAustralia
| | - Jody A. O'Connor
- Department for Environment and WaterAdelaideSouth AustraliaAustralia
| | - Justin D. Brookes
- School of Biological SciencesThe University of AdelaideAdelaideSouth AustraliaAustralia
| | - Phillip Cassey
- School of Biological SciencesThe University of AdelaideAdelaideSouth AustraliaAustralia
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8
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Beltran RS, Hernandez KM, Condit R, Robinson PW, Crocker DE, Goetsch C, Kilpatrick AM, Costa DP. Physiological tipping points in the relationship between foraging success and lifetime fitness of a long-lived mammal. Ecol Lett 2023; 26:706-716. [PMID: 36888564 DOI: 10.1111/ele.14193] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 03/09/2023]
Abstract
Although anthropogenic change is often gradual, the impacts on animal populations may be precipitous if physiological processes create tipping points between energy gain, reproduction or survival. We use 25 years of behavioural, diet and demographic data from elephant seals to characterise their relationships with lifetime fitness. Survival and reproduction increased with mass gain during long foraging trips preceding the pupping seasons, and there was a threshold where individuals that gained an additional 4.8% of their body mass (26 kg, from 206 to 232 kg) increased lifetime reproductive success three-fold (from 1.8 to 4.9 pups). This was due to a two-fold increase in pupping probability (30% to 76%) and a 7% increase in reproductive lifespan (6.0 to 6.4 years). The sharp threshold between mass gain and reproduction may explain reproductive failure observed in many species and demonstrates how small, gradual reductions in prey from anthropogenic disturbance could have profound implications for animal populations.
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Affiliation(s)
- Roxanne S Beltran
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Keith M Hernandez
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA.,Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, California, USA
| | - Richard Condit
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Patrick W Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, California, USA
| | - Chandra Goetsch
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - A Marm Kilpatrick
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, USA.,Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, California, USA
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9
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Van de Walle J, Larue B, Pigeon G, Pelletier F. Different proxies, different stories? Imperfect correlations and different determinants of fitness in bighorn sheep. Ecol Evol 2022; 12:e9582. [PMID: 36514553 PMCID: PMC9731912 DOI: 10.1002/ece3.9582] [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: 11/09/2022] [Accepted: 11/16/2022] [Indexed: 12/13/2022] Open
Abstract
Measuring individual fitness empirically is required to assess selective pressures and predicts evolutionary changes in nature. There is, however, little consensus on how fitness should be empirically estimated. As fitness proxies vary in their underlying assumptions, their relative sensitivity to individual, environmental, and demographic factors may also vary. Here, using a long-term study, we aimed at identifying the determinants of individual fitness in bighorn sheep (Ovis canadensis) using seven fitness proxies. Specifically, we compared four-lifetime fitness proxies: lifetime breeding success, lifetime reproductive success, individual growth rate, individual contribution to population growth, and three multi-generational proxies: number of granddaughters, individual descendance in the next generation, and relative genetic contribution to the next generation. We found that all proxies were positively correlated, but the magnitude of the correlations varied substantially. Longevity was the main determinant of most fitness proxies. Individual fitness calculated over more than one generation was also affected by population density and growth rate. Because they are affected by contrasting factors, our study suggests that different fitness proxies should not be used interchangeably as they may convey different information about selective pressures and lead to divergent evolutionary predictions. Uncovering the mechanisms underlying variation in individual fitness and improving our ability to predict evolutionary change might require the use of several, rather than one, the proxy of individual fitness.
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Affiliation(s)
- Joanie Van de Walle
- Biology DepartmentWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
| | - Benjamin Larue
- Département de BiologieUniversité de SherbrookeSherbrookeQuébecCanada
| | - Gabriel Pigeon
- Institut de recherche sur les forêtsUniversité du Québec en Abitibi‐TémiscamingueRouyn‐NorandaQuébecCanada
| | - Fanie Pelletier
- Département de BiologieUniversité de SherbrookeSherbrookeQuébecCanada
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10
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Bauld JT, Abernethy KA, Newton J, Lehmann D, Jones IL, Bussière LF. Can diet niche partitioning enhance sexual dimorphism? Ecol Evol 2022; 12:e9599. [PMID: 36545364 PMCID: PMC9760898 DOI: 10.1002/ece3.9599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 11/01/2022] [Accepted: 11/20/2022] [Indexed: 12/23/2022] Open
Abstract
Classic evolutionary theory suggests that sexual dimorphism evolves primarily via sexual and fecundity selection. However, theory and evidence are beginning to accumulate suggesting that resource competition can drive the evolution of sexual dimorphism, via ecological character displacement between sexes. A key prediction of this hypothesis is that the extent of ecological divergence between sexes will be associated with the extent of sexual dimorphism. As the stable isotope ratios of animal tissues provide a quantitative measure of various aspects of ecology, we carried out a meta-analysis examining associations between the extent of isotopic divergence between sexes and the extent of body size dimorphism. Our models demonstrate that large amounts of between-study variation in isotopic (ecological) divergence between sexes is nonrandom and may be associated with the traits of study subjects. We, therefore, completed meta-regressions to examine whether the extent of isotopic divergence between sexes is associated with the extent of sexual size dimorphism. We found modest but significantly positive associations across species between size dimorphism and ecological differences between sexes, that increased in strength when the ecological opportunity for dietary divergence between sexes was greatest. Our results, therefore, provide further evidence that ecologically mediated selection, not directly related to reproduction, can contribute to the evolution of sexual dimorphism.
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Affiliation(s)
- Joshua T. Bauld
- Biological and Environmental SciencesUniversity of StirlingStirlingUK
| | - Katharine A. Abernethy
- Biological and Environmental SciencesUniversity of StirlingStirlingUK
- Institut de Recherche en Ecologie TropicaleCENARESTLibrevilleGabon
| | - Jason Newton
- National Environmental Isotope FacilityScottish Universities Environmental Research CentreEast KilbrideUK
| | - David Lehmann
- Agence Nationale des Parcs Nationaux (ANPN)LibrevilleGabon
| | - Isabel L. Jones
- Biological and Environmental SciencesUniversity of StirlingStirlingUK
| | - Luc F. Bussière
- Biology and Environmental Sciences and Gothenburg Global Biodiversity CentreUniversity of GothenburgGothenburgSweden
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11
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Péron G. Reproductive skews of territorial species in heterogeneous landscapes. OIKOS 2022. [DOI: 10.1111/oik.09627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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McHuron EA, Adamczak S, Arnould JPY, Ashe E, Booth C, Bowen WD, Christiansen F, Chudzinska M, Costa DP, Fahlman A, Farmer NA, Fortune SME, Gallagher CA, Keen KA, Madsen PT, McMahon CR, Nabe-Nielsen J, Noren DP, Noren SR, Pirotta E, Rosen DAS, Speakman CN, Villegas-Amtmann S, Williams R. Key questions in marine mammal bioenergetics. CONSERVATION PHYSIOLOGY 2022; 10:coac055. [PMID: 35949259 PMCID: PMC9358695 DOI: 10.1093/conphys/coac055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/28/2022] [Accepted: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Bioenergetic approaches are increasingly used to understand how marine mammal populations could be affected by a changing and disturbed aquatic environment. There remain considerable gaps in our knowledge of marine mammal bioenergetics, which hinder the application of bioenergetic studies to inform policy decisions. We conducted a priority-setting exercise to identify high-priority unanswered questions in marine mammal bioenergetics, with an emphasis on questions relevant to conservation and management. Electronic communication and a virtual workshop were used to solicit and collate potential research questions from the marine mammal bioenergetic community. From a final list of 39 questions, 11 were identified as 'key' questions because they received votes from at least 50% of survey participants. Key questions included those related to energy intake (prey landscapes, exposure to human activities) and expenditure (field metabolic rate, exposure to human activities, lactation, time-activity budgets), energy allocation priorities, metrics of body condition and relationships with survival and reproductive success and extrapolation of data from one species to another. Existing tools to address key questions include labelled water, animal-borne sensors, mark-resight data from long-term research programs, environmental DNA and unmanned vehicles. Further validation of existing approaches and development of new methodologies are needed to comprehensively address some key questions, particularly for cetaceans. The identification of these key questions can provide a guiding framework to set research priorities, which ultimately may yield more accurate information to inform policies and better conserve marine mammal populations.
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Affiliation(s)
- Elizabeth A McHuron
- Corresponding author: Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington, WA, 98195, USA.
| | - Stephanie Adamczak
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
| | - John P Y Arnould
- School of Life and Environmental Sciences, Deakin University, Burwood, VIC 3125, Australia
| | - Erin Ashe
- Oceans Initiative, Seattle, WA, 98102, USA
| | - Cormac Booth
- SMRU Consulting, Scottish Oceans Institute, University of St. Andrews, St. Andrews KY16 8LB, UK
| | - W Don Bowen
- Biology Department, Dalhousie University, Halifax, NS B3H 4R2, Canada
- Population Ecology Division, Bedford Institute of Oceanography, Dartmouth, NS B2Y 4A2, Canada
| | - Fredrik Christiansen
- Aarhus Institute of Advanced Studies, 8000 Aarhus C, Denmark
- Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
- Center for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch, Murdoch University, WA 6150, Australia
| | - Magda Chudzinska
- SMRU Consulting, Scottish Oceans Institute, University of St. Andrews, St. Andrews KY16 8LB, UK
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St. Andrews, St. Andrews KY16 9XL, UK
| | - Daniel P Costa
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
| | - Andreas Fahlman
- Fundación Oceanogràfic de la Comunitat Valenciana, 46005 Valencia, Spain
- Kolmården Wildlife Park, 618 92 Kolmården, Sweden
| | - Nicholas A Farmer
- NOAA/National Marine Fisheries Service, Southeast Regional Office, St. Petersburg, FL, 33701, USA
| | - Sarah M E Fortune
- Department of Oceanography, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Cara A Gallagher
- Plant Ecology and Nature Conservation, University of Potsdam, 14476 Potsdam, Germany
| | - Kelly A Keen
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
| | - Peter T Madsen
- Zoophysiology, Department of Biology, Aarhus University, 8000 Aarhus C, Denmark
| | - Clive R McMahon
- IMOS Animal Tagging, Sydney Institute of Marine Science, Mosman, NSW 2088, Australia
| | | | - Dawn P Noren
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, 98112, USA
| | - Shawn R Noren
- Institute of Marine Science, University of California Santa Cruz, Santa Cruz, CA, 95060, USA
| | - Enrico Pirotta
- Centre for Research into Ecological and Environmental Modelling, University of St. Andrews, St. Andrews KY16 9LZ, UK
| | - David A S Rosen
- Institute for Oceans and Fisheries, University of British Columbia, Vancouver, BC V6T 1ZA, Canada
| | - Cassie N Speakman
- School of Life and Environmental Sciences, Deakin University, Burwood, VIC 3125, Australia
| | - Stella Villegas-Amtmann
- Ecology and Evolutionary Biology Department, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
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13
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Curren LJ, Sawdy MA, Scribner KT, Lehmann KDS, Holekamp KE. Endurance rivalry among male spotted hyenas: what does it mean to “endure”? Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03212-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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14
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Arce F, Hindell MA, McMahon CR, Wotherspoon SJ, Guinet C, Harcourt RG, Bestley S. Elephant seal foraging success is enhanced in Antarctic coastal polynyas. Proc Biol Sci 2022; 289:20212452. [PMID: 35078353 PMCID: PMC8790345 DOI: 10.1098/rspb.2021.2452] [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: 11/09/2021] [Accepted: 12/02/2021] [Indexed: 01/28/2023] Open
Abstract
Antarctic polynyas are persistent open water areas which enable early and large seasonal phytoplankton blooms. This high primary productivity, boosted by iron supply from coastal glaciers, attracts organisms from all trophic levels to form a rich and diverse community. How the ecological benefit of polynya productivity is translated to the highest trophic levels remains poorly resolved. We studied 119 southern elephant seals feeding over the Antarctic shelf and demonstrated that: (i) 96% of seals foraging here used polynyas, with individuals spending on average 62% of their time there; (ii) the seals exhibited more area-restricted search behaviour when in polynyas; and (iii) these seals gained more energy (indicated by increased buoyancy from greater fat stores) when inside polynyas. This higher-quality foraging existed even when ice was not present in the study area, indicating that these are important and predictable foraging grounds year-round. Despite these energetic advantages from using polynyas, not all the seals used them extensively. Factors other than food supply may influence an individual's choice in their use of feeding grounds, such as exposure to predation or the probability of being able to return to distant sub-Antarctic breeding sites.
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Affiliation(s)
- Fernando Arce
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
- Australian Antarctic Division, 203 Channel Highway, Kingston, TAS 7050, Australia
| | - Mark A. Hindell
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
| | - Clive R. McMahon
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
- IMOS Animal Tagging, Sydney Institute of Marine Science, Mosman, NSW 2088, Australia
- Department of Biological Sciences, Macquarie University, North Ryde, NSW 2113, Australia
| | - Simon J. Wotherspoon
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
- Australian Antarctic Division, 203 Channel Highway, Kingston, TAS 7050, Australia
| | - Christophe Guinet
- Centre d'Etudes Biologiques de Chizé, CNRS, Villiers en Bois 79360, France
| | - Robert G. Harcourt
- Department of Biological Sciences, Macquarie University, North Ryde, NSW 2113, Australia
| | - Sophie Bestley
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
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15
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Kienle SS, Friedlaender AS, Crocker DE, Mehta RS, Costa DP. Trade-offs between foraging reward and mortality risk drive sex-specific foraging strategies in sexually dimorphic northern elephant seals. ROYAL SOCIETY OPEN SCIENCE 2022; 9:210522. [PMID: 35116140 PMCID: PMC8767210 DOI: 10.1098/rsos.210522] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 12/14/2021] [Indexed: 05/04/2023]
Abstract
Sex-specific phenotypic differences are widespread throughout the animal kingdom. Reproductive advantages provided by trait differences come at a cost. Here, we link sex-specific foraging strategies to trade-offs between foraging reward and mortality risk in sexually dimorphic northern elephant seals (Mirounga angustirostris). We analyse a decadal dataset on movement patterns, dive behaviour, foraging success and mortality rates. Females are deep-diving predators in open ocean habitats. Males are shallow-diving benthic predators in continental shelf habitats. Males gain six times more mass and acquire energy 4.1 times faster than females. High foraging success comes with a high mortality rate. Males are six times more likely to die than females. These foraging strategies and trade-offs are related to different energy demands and life-history strategies. Males use a foraging strategy with a high mortality risk to attain large body sizes necessary to compete for females, as only a fraction of the largest males ever mate. Females use a foraging strategy with a lower mortality risk, maximizing reproductive success by pupping annually over a long lifespan. Our results highlight how sex-specific traits can drive disparity in mortality rates and expand species' niche space. Further, trade-offs between foraging rewards and mortality risk can differentially affect each sex's ability to maximize fitness.
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Affiliation(s)
- Sarah S. Kienle
- Ecology and Evolutionary Biology, University of California, 130 McAllister Way, Santa Cruz, CA 95060, USA
- Department of Biology, Baylor University, One Bear Place #97399, Waco, TX 76798, USA
| | - Ari S. Friedlaender
- Ocean Science, University of California, 130 McAllister Way, Santa Cruz, CA 95060, USA
| | - Daniel E. Crocker
- Biology, Sonoma State University, 1801 East Cotati Avenue, Rohnert Park, CA 94928, USA
| | - Rita S. Mehta
- Ecology and Evolutionary Biology, University of California, 130 McAllister Way, Santa Cruz, CA 95060, USA
| | - Daniel P. Costa
- Ecology and Evolutionary Biology, University of California, 130 McAllister Way, Santa Cruz, CA 95060, USA
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16
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Linossier J, Casey C, Charrier I, Mathevon N, Reichmuth C. Maternal responses to pup calls in a high-cost lactation species. Biol Lett 2021; 17:20210469. [PMID: 34932922 PMCID: PMC8692032 DOI: 10.1098/rsbl.2021.0469] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 11/15/2021] [Indexed: 12/24/2022] Open
Abstract
Bonding between mothers and their young is fundamental to mammalian reproductive behaviour and individual fitness. In social systems where the risk of confusing filial and non-filial offspring is high, mothers should demonstrate early, strong and consistent responses to their kin throughout the period of offspring dependence, irrespective of maternal traits. We tested this hypothesis through playback experiments in the northern elephant seal Mirounga angustirostris, a phocid species that breeds in high-density colonies. We found that mothers recognized their offspring throughout lactation and as early as 1-2 days after parturition. Measures of experience (age) and temperament (aggressivity) did not predict their response strength to filial playback treatments, nor did pup age or sex. Some mothers showed great consistency in behavioural responses throughout the lactation period, while others were less predictable. The strength of a female's response did not influence her pup's weaning weight; however, more consistent females weaned pups of higher mass. This is a rare demonstration of individual recognition among phocid mothers and their offspring, and suggests that consistency in maternal responsiveness may be an important social factor influencing the pup's growth and survival.
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Affiliation(s)
- Juliette Linossier
- Institute of Marine Sciences, Long Marine Laboratory, University of California Santa Cruz, Santa Cruz, CA 95060, USA
- Biophonia, Sualello 20232, Oletta, France
| | - Caroline Casey
- Institute of Marine Sciences, Long Marine Laboratory, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Isabelle Charrier
- Université Paris-Saclay, CNRS, UMR 9197, Institut des Neurosciences Paris-Saclay, Orsay 91405, France
| | - Nicolas Mathevon
- Equipe Neuro-Ethologie Sensorielle ENES / CRNL, University of Lyon / Saint-Etienne, CNRS, Inserm, 42100 Saint-Etienne, France
| | - Colleen Reichmuth
- Institute of Marine Sciences, Long Marine Laboratory, University of California Santa Cruz, Santa Cruz, CA 95060, USA
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17
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Holser RR, Crocker DE, Robinson PW, Condit R, Costa DP. Density-dependent effects on reproductive output in a capital breeding carnivore, the northern elephant seal ( Mirounga angustirostris). Proc Biol Sci 2021; 288:20211258. [PMID: 34641731 PMCID: PMC8511744 DOI: 10.1098/rspb.2021.1258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 09/17/2021] [Indexed: 11/12/2022] Open
Abstract
All organisms face resource limitations that will ultimately restrict population growth, but the controlling mechanisms vary across ecosystems, taxa, and reproductive strategies. Using four decades of data, we examine how variation in the environment and population density affect reproductive outcomes in a capital-breeding carnivore, the northern elephant seal (Mirounga angustirostris). This species provides a unique opportunity to examine the relative importance of resource acquisition and density-dependence on breeding success. Capital breeders accrue resources over large temporal and spatial scales for use during an abbreviated reproductive period. This strategy may have evolved, in part, to confer resilience to short-term environmental variability. We observed density-dependent effects on weaning mass, and maternal age (experience) was more important than oceanographic conditions or maternal mass in determining offspring weaning mass. Together these findings show that the mechanisms controlling reproductive output are conserved across terrestrial and marine systems and vary with population dynamics, an important consideration when assessing the effect of extrinsic changes, such as climate change, on a population.
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Affiliation(s)
- Rachel R. Holser
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 130 McAllister Way, Santa Cruz, CA 95060, USA
| | - Daniel E. Crocker
- Department of Biology, Sonoma State University, Rohnert Park, CA 94928, USA
| | - Patrick W. Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 130 McAllister Way, Santa Cruz, CA 95060, USA
| | - Richard Condit
- Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL 60605, USA
- Morton Arboretum, 4100 Illinois Route 53, Lisle, IL 60532, USA
| | - Daniel P. Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 130 McAllister Way, Santa Cruz, CA 95060, USA
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18
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Wolf AM. The tumor suppression theory of aging. Mech Ageing Dev 2021; 200:111583. [PMID: 34637937 DOI: 10.1016/j.mad.2021.111583] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/01/2021] [Accepted: 10/05/2021] [Indexed: 01/10/2023]
Abstract
Despite continued increases in human life expectancy, the factors determining the rate of human biological aging remain unknown. Without understanding the molecular mechanisms underlying aging, efforts to prevent aging are unlikely to succeed. The tumor suppression theory of aging introduced here proposes somatic mutation as the proximal cause of aging, but postulates that oncogenic transformation and clonal expansion, not functional impairment, are the relevant consequences of somatic mutation. Obesity and caloric restriction accelerate and decelerate aging due to their effect on cell proliferation, during which most mutations arise. Most phenotypes of aging are merely tumor-suppressive mechanisms that evolved to limit malignant growth, the dominant age-related cause of death in early and middle life. Cancer limits life span for most long-lived mammals, a phenomenon known as Peto's paradox. Its conservation across species demonstrates that mutation is a fundamental but hard limit on mammalian longevity. Cell senescence and apoptosis and differentiation induced by oncogenes, telomere shortening or DNA damage evolved as a second line of defense to limit the tumorigenic potential of clonally expanding cells, but accumulating senescent cells, senescence-associated secretory phenotypes and stem cell exhaustion eventually cause tissue dysfunction and the majority, if not most, phenotypes of aging.
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Affiliation(s)
- Alexander M Wolf
- Laboratory for Morphological and Biomolecular Imaging, Faculty of Medicine, Nippon Medical School, Sendagi 1-1-5, Bunkyo-ku, Tokyo, Japan.
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19
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Hindell MA, McMahon CR, Jonsen I, Harcourt R, Arce F, Guinet C. Inter- and intrasex habitat partitioning in the highly dimorphic southern elephant seal. Ecol Evol 2021; 11:1620-1633. [PMID: 33613994 PMCID: PMC7882946 DOI: 10.1002/ece3.7147] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/25/2020] [Accepted: 12/02/2020] [Indexed: 01/15/2023] Open
Abstract
Partitioning resources is a key mechanism for avoiding intraspecific competition and maximizing individual energy gain. However, in sexually dimorphic species it is difficult to discern if partitioning is due to competition or the different resource needs of morphologically distinct individuals. In the highly dimorphic southern elephant seal, there are intersexual differences in habitat use; at Iles Kerguelen, males predominantly use shelf waters, while females use deeper oceanic waters. There are equally marked intrasexual differences, with some males using the nearby Kerguelen Plateau, and others using the much more distant Antarctic continental shelf (~2,000 km away). We used this combination of inter and intrasexual behavior to test two hypotheses regarding habitat partitioning in highly dimorphic species. (a) that intersexual differences in habitat use will not appear until the seals diverge in body size and (b) that some habitats have higher rates of energy return than others. In particular, that the Antarctic shelf would provide higher energy returns than the Kerguelen Shelf, to offset the greater cost of travel. We quantified the habitat use of 187 southern elephant seals (102 adult females and 85 subadult males). The seals in the two groups were the same size (~2.4 m) removing the confounding effect of body size. We found that the intersexual differences in habitat use existed before the divergence in body size. Also, we found that the amount of energy gained was the same in all of the major habitats. This suggests that the use of shelf habitats by males is innate, and a trade-off between the need to access the large benthic prey available on shelf waters, against the higher risk of predation there. Intrasexual differences in habitat use are another trade-off; although there are fewer predators on the Antarctic shelf, it is subject to considerable interannual fluctuations in sea-ice extent. In contrast, the Kerguelen Plateau presents more consistent foraging opportunities, but contains higher levels of predation. Habitat partitioning in this highly dimorphic species is therefore the result of complex interplay of life history strategies, environmental conditions and predation pressure.
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Affiliation(s)
- Mark A. Hindell
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Clive R. McMahon
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTasmaniaAustralia
- IMOS Animal Tagging, Sydney Institute of Marine ScienceMosmanNew South WalesAustralia
- Department of Biological SciencesMacquarie UniversityNorth Ryde, SydneyNew South WalesAustralia
| | - Ian Jonsen
- Department of Biological SciencesMacquarie UniversityNorth Ryde, SydneyNew South WalesAustralia
| | - Robert Harcourt
- IMOS Animal Tagging, Sydney Institute of Marine ScienceMosmanNew South WalesAustralia
- Department of Biological SciencesMacquarie UniversityNorth Ryde, SydneyNew South WalesAustralia
| | - Fernando Arce
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Christophe Guinet
- Centre d’Etudes Biologiques de Chizé (CEBC)UMR 7372Université de la Rochelle‐CNRSVilliers en BoisFrance
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20
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Berzins LL, Dawson RD, Morrissey CA, Clark RG. The relative contribution of individual quality and changing climate as drivers of lifetime reproductive success in a short-lived avian species. Sci Rep 2020; 10:19766. [PMID: 33188255 PMCID: PMC7666198 DOI: 10.1038/s41598-020-75557-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 09/22/2020] [Indexed: 12/12/2022] Open
Abstract
Animal populations are influenced strongly by fluctuations in weather conditions, but long-term fitness costs are rarely explored, especially in short-lived avian species. We evaluated the relative contributions of individual characteristics and environmental conditions to lifetime reproductive success (LRS) of female tree swallows (Tachycineta bicolor) from two populations breeding in contrasting environments and geographies, Saskatchewan and British Columbia, Canada. Female swallows achieved higher LRS by breeding early in the season and producing more fledglings. Other measures of female quality had virtually no influence on LRS. Genetic factors did not predict LRS, as there was no correlation between life-history components for sister pairs nor between mothers and their daughters. Instead, climate variability-indexed by spring pond density (i.e., abundance of wetland basins holding water) during years when females bred-had strong positive effects on female LRS in more arid Saskatchewan but only weak positive effects of moisture conditions were detected in wetter British Columbia. Overall, several life history trait correlates of LRS were similar between populations, but local environmental factors experienced by individuals while breeding produced large differences in LRS. Consequently, variable and extreme environmental conditions associated with changing climate are predicted to influence individual fitness of distinct populations within a species' range.
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Affiliation(s)
- Lisha L Berzins
- Department of Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E2, Canada.
| | - Russell D Dawson
- Ecosystem Science and Management Program, University of Northern British Columbia, Prince George, BC, V2N 4Z9, Canada
| | - Christy A Morrissey
- Department of Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E2, Canada
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, S7N 5C8, Canada
| | - Robert G Clark
- Department of Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E2, Canada
- Environment and Climate Change Canada, Saskatoon, SK, S7N 0X4, Canada
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21
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Nepomnaschy PA, Rowlands A, Prescivalli Costa AP, Salvante KG. Socio-Ecological Challenges as Modulators of Women's Reproductive Trajectories. ANNUAL REVIEW OF ANTHROPOLOGY 2020. [DOI: 10.1146/annurev-anthro-102317-045930] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Amenorrhea, anovulatory cycles, miscarriages, and other reproductive outcomes are often seen as pathological. Life history theory, in contrast, treats those outcomes as adaptations that helped women optimize the timing of reproductive ventures across our evolutionary history. Women's bodies adjust their reproductive strategies in response to socio-ecological conditions, a process mediated by the hypothalamic-pituitary-adrenal axis (HPAA). Here, we review the links between socio-ecological conditions, HPAA activity, and the pace of women's reproductive transitions such as puberty, age at first birth, interbirth interval, and perimenopause. We also discuss the HPAA's role as a modulator of reproductive function: It not only suppresses it but may also prime women's bodies for future reproductive ventures. We conclude by reviewing challenges and opportunities within our subfield, including the need for transdisciplinary teams to develop longitudinal studies to improve our understanding of women's reproductive trajectories and outcomes from the moment they are conceived.
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Affiliation(s)
- Pablo A. Nepomnaschy
- Maternal and Child Health Laboratory, Faculty of Health Sciences; and Crawford Laboratory of Evolutionary Studies, Department of Biological Sciences, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada;, , ,
| | - Amanda Rowlands
- Maternal and Child Health Laboratory, Faculty of Health Sciences; and Crawford Laboratory of Evolutionary Studies, Department of Biological Sciences, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada;, , ,
| | - Ana Paula Prescivalli Costa
- Maternal and Child Health Laboratory, Faculty of Health Sciences; and Crawford Laboratory of Evolutionary Studies, Department of Biological Sciences, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada;, , ,
| | - Katrina G. Salvante
- Maternal and Child Health Laboratory, Faculty of Health Sciences; and Crawford Laboratory of Evolutionary Studies, Department of Biological Sciences, Faculty of Science, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada;, , ,
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22
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Pierotti R. Historical links between Ethnobiology and Evolution: Conflicts and possible resolutions. STUDIES IN HISTORY AND PHILOSOPHY OF BIOLOGICAL AND BIOMEDICAL SCIENCES 2020; 81:101277. [PMID: 32238300 DOI: 10.1016/j.shpsc.2020.101277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 02/11/2020] [Accepted: 03/11/2020] [Indexed: 06/11/2023]
Abstract
In recent years there have been several attempts to examine Ethnobiology from an evolutionary perspective. I discuss several potential sources of confusion in applying Evolutionary concepts to Ethnobiology. Ethnobiological discussions of evolution have focused more on changes in human populations, or on human impacts upon plants used by humans for a variety of purposes, than on the processes typically emphasized in discussions by biologists studying evolution. There has been little acknowledgment of how the field of biological evolution is changing in the 21st Century. In this article I focus on recent developments in evolutionary thinking that could be effectively integrated into Ethnobiological concepts. These include: 1) The increased importance of individual organisms in understanding both population dynamics and microevolutionary change (i.e. natural selection). This change in focus creates the potential for incorporating understandings from Indigenous people who recognize a different set of dynamics that govern how both plant and animal populations are regulated, leading to new insights into how conservation practices should be enacted; 2) Niche Construction, which is a 21st century concept that argues that organisms shape their own environments and those of other species. This approach creates a new way of looking at how Natural Selection can act upon a wide range of organisms; and finally, 3) Reticulate Evolution, in which different species exchange genetic material as a result of behavioral or physiological interactions with major evolutionary consequences. These concepts relate strongly to fundamental Indigenous conceptions of ecosystem functioning, including the ideas that All Things are Connected and that All Life Forms are Related. I argue that Ethnobiology and Indigenous Knowledge are strongest in dealing with phenomena linked to behavior and ecology, which are fields being neglected by many contemporary molecular approaches to understanding evolution. Attempts to deal with Conservation in a world subject to climate change would be greatly improved by working closely with Indigenous peoples and incorporating concepts from these traditions into practices on a global scale.
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Affiliation(s)
- Raymond Pierotti
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, 66045, USA.
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