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Vasilieva NA, Savinetskaya LE, Tchabovsky AV. Juvenile survival curves in a solitary ground squirrel with a prolonged hibernation: effects of individual characteristics, environment, and maternal investment. Curr Zool 2024; 70:13-23. [PMID: 38476132 PMCID: PMC10926259 DOI: 10.1093/cz/zoac097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 11/26/2022] [Indexed: 03/14/2024] Open
Abstract
Juvenile survival is a key life-history influence on population dynamics and adaptive evolution. We analyzed the effects of individual characteristics, early environment, and maternal investment on juvenile survival in a large solitary hibernating rodent-yellow ground squirrel Spermophilus fulvus using Cox mixed-effects models. Only 48% of weaned pups survived to dispersal and 17% survived to hibernation. Early life expectancy was primarily determined by individual characteristics and, to a lesser extent, by the early environment. The strongest and positive predictor of juvenile survival was body mass which crucially affected mortality immediately after weaning. Males suffered higher mortality than females after the onset of dispersal; however, the overall difference between sexes was partly masked by high rates of mortality in the first days after emergence in both sexes. Later emerged juveniles had lower life expectancy than the earliest pups. The overall effect of local juvenile density was positive. Prolonged lactation did not enhance juvenile survival: Pups nursed longer survived shorter than the young nursed for a shorter period. Our findings support the hypothesis that females of S. fulvus cannot effectively regulate maternal expenditures to mitigate the effects of unfavorable conditions on their offspring. The strategy to deal with seasonal time constraints on life history in female S. fulvus suggests an early termination of maternal care at the cost of juvenile quality and survival. This female reproductive strategy corresponds to a "fast-solitary" life of folivorous desert-dwelling S. fulvus and other solitary ground squirrels with prolonged hibernation.
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Affiliation(s)
- Nina A Vasilieva
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow 119071, Russia
| | - Liudmila E Savinetskaya
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow 119071, Russia
| | - Andrey V Tchabovsky
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow 119071, Russia
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Lamb S, McMillan BR, van de Kerk M, Frandsen PB, Hersey KR, Larsen RT. From conception to recruitment: Nutritional condition of the dam dictates the likelihood of success in a temperate ungulate. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1090116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023] Open
Abstract
Maternal effects are the influence of maternal phenotype and the maternally-provided environment on the phenotype (i.e., expression of traits) of offspring. Frequently, maternal effects are manifest both before and after parturition. Pre-parturition effects are primarily direct allocation of energy to the offspring that is in utero. Post-parturition effects can include direct (e.g., nursing and defending offspring) and indirect (e.g., selection of habitat that is relatively safe or has high nutritional value) influences. While both direct and indirect effects are often discussed, there is a paucity of information on the relative importance of each type on offspring due to the difficulty in monitoring mothers prior to parturition and mother-offspring relationships after parturition in free-ranging animals. Our objective was to determine the importance of direct maternal effects on birth weight, growth rates, and survival of mule deer (Odocoileus hemionus) fawns from birth through the first 18 months of life. We determined the effect of nutritional condition of the dam (mother) on birth weight (pre-parturition direct effect). We also examined the post-parturition direct effect of dam nutritional condition on growth rates and survival of fawns. Direct maternal effects were evident both before and after parturition; dams in better nutritional condition produced offspring with greater mass at birth, higher rates of growth, and increased survival. Our findings demonstrate that maternal nutritional condition influences fawn health from gestation through recruitment. These links highlight the importance of considering direct maternal effects when examining population dynamics and reproductive success in long-lived mammals. Management plans for ungulates should include assessment of nutritional condition of adult females to maximize likelihood of effective conservation.
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3
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Watkins BE, Bergman EJ, Dhaseleer LC, Bernal LJ. Factors influencing productivity and recruitment of elk in northern New Mexico. J Wildl Manage 2022. [DOI: 10.1002/jwmg.22348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Bruce E. Watkins
- Vermejo Park Ranch, Turner Enterprises, P.O. Drawer E, Raton NM 87740 USA
| | - Eric J. Bergman
- Colorado Parks and Wildlife, 317 Prospect Road Fort Collins CO 80526 USA
| | | | - Lance J. Bernal
- Vermejo Park Ranch, Turner Enterprises, P.O. Drawer E, Raton NM 87740 USA
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Ruprecht J, Forrester TD, Jackson NJ, Clark DA, Wisdom MJ, Rowland MM, Smith JB, Stewart KM, Levi T. A seasonal pulse of ungulate neonates influences space use by carnivores in a multi-predator, multi-prey system. Ecol Evol 2022; 12:e9389. [PMID: 36254298 PMCID: PMC9558345 DOI: 10.1002/ece3.9389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 07/27/2022] [Accepted: 08/28/2022] [Indexed: 11/08/2022] Open
Abstract
The behavioral mechanisms by which predators encounter prey are poorly resolved. In particular, the extent to which predators engage in active search for prey versus incidentally encountering them has not been well studied in many systems and particularly not for neonate prey during the birth pulse. Parturition of many large herbivores occurs during a short and predictable temporal window in which young are highly vulnerable to predation. Our study aims to determine how a suite of carnivores responds to the seasonal pulse of newborn ungulates using contemporaneous global positioning system (GPS) locations of four species of predators and two species of prey. We used step-selection functions to assess whether coyotes, cougars, black bears, and bobcats encountered parturient adult female ungulates more often than expected by chance in a low-density population of mule deer and a high-density population of elk. We then assessed whether the carnivore species that encountered parturient prey more often than expected by chance did so by shifting their habitat use toward areas with a high probability of encountering neonates. None of the four carnivore species encountered GPS-collared parturient mule deer more often than expected by chance. By contrast, we determined that cougar and male bear movements positioned them in the proximity of GPS-collared parturient elk more often than expected by chance which may provide evidence of searching behavior. Although both male bears and cougars exhibited behavior consistent with active search for neonates, only male bears used elk parturition habitat in a way that dynamically tracked the phenology of the elk birth pulse suggesting that maximizing encounters with juvenile elk was a motivation when selecting resources. Our results suggest that there is high interspecific and intersexual variability in foraging strategies among large mammalian predators and their prey.
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Affiliation(s)
- Joel Ruprecht
- Department of Fisheries, Wildlife, and Conservation SciencesOregon State UniversityCorvallisOregonUSA
| | | | - Nathan J. Jackson
- Department of Natural Resources and Environmental ScienceUniversity of Nevada, RenoRenoNevadaUSA
| | | | - Michael J. Wisdom
- US Department of Agriculture Forest Service Pacific Northwest Research StationLa GrandeOregonUSA
| | - Mary M. Rowland
- US Department of Agriculture Forest Service Pacific Northwest Research StationLa GrandeOregonUSA
| | | | - Kelley M. Stewart
- Department of Natural Resources and Environmental ScienceUniversity of Nevada, RenoRenoNevadaUSA
| | - Taal Levi
- Department of Fisheries, Wildlife, and Conservation SciencesOregon State UniversityCorvallisOregonUSA
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5
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Cook RC, Shipley LA, Cook JG, Camp MJ, Monzingo DS, Robatcek SL, Berry SL, Hull IT, Myers WL, Denryter K, Long RA. Sequential detergent fiber assay results used for nutritional ecology research: Evidence of bias since 2012. WILDLIFE SOC B 2022. [DOI: 10.1002/wsb.1348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Rachel C. Cook
- National Council of Air and Stream Improvement 1401 Gekeler Lane La Grande OR 97850 USA
| | - Lisa A. Shipley
- 1229 Webster Hall, School of the Environment Washington State University Pullman WA 99164‐2812 USA
| | - John G. Cook
- National Council of Air and Stream Improvement 1401 Gekeler Lane La Grande OR 97850 USA
| | - Meghan J. Camp
- Washington State University Vogel Plant Biosciences 136, School of the Environment, Pullman, WA 99164‐2812; Cramer Fish Sciences 1125 12th Ave. NW, Suite B‐1 Issaquah WA 98027 USA
| | - Deborah S. Monzingo
- 1229 Webster Hall, School of the Environment Washington State University Pullman WA 99164‐2812 USA
| | | | | | - Iver T. Hull
- 1229 Webster Hall, School of the Environment Washington State University Pullman WA 99164‐2812 USA
| | - Woodrow L. Myers
- Washington Department of Fish and Wildlife 2315 N Discovery Place Spokane Valley WA 99216 USA
| | - Kristin Denryter
- California Department of Fish and Wildlife 1010 Riverside Parkway West Sacramento CA 95605 USA
| | - Ryan A. Long
- Department of Fish and Wildlife Sciences University of Idaho Moscow ID 83844 USA
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Turnley MT, Larsen RT, Hersey KR, Sallee DW, Hinton MS, McMillan BR. Optimizing methods for capturing neonate elk when using vaginal implant transmitters. WILDLIFE SOC B 2022. [DOI: 10.1002/wsb.1326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Matthew T. Turnley
- Department of Plant and Wildlife Sciences Brigham Young University 4105 Life Sciences Building Provo UT 84602 USA
| | - Randy T. Larsen
- Department of Plant and Wildlife Sciences Brigham Young University 4105 Life Sciences Building Provo UT 84602 USA
| | - Kent R. Hersey
- Utah Division of Wildlife Resources 1594 W North Temple Street, Suite 2110 Salt Lake City UT 84114 USA
| | - Daniel W Sallee
- Department of Plant and Wildlife Sciences Brigham Young University 4105 Life Sciences Building Provo UT 84602 USA
| | - Morgan S. Hinton
- Department of Plant and Wildlife Sciences Brigham Young University 4105 Life Sciences Building Provo UT 84602 USA
| | - Brock R. McMillan
- Department of Plant and Wildlife Sciences Brigham Young University 4105 Life Sciences Building Provo UT 84602 USA
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Denryter K, Cook RC, Cook JG, Parker KL. Animal‐defined resources reveal nutritional inadequacies for woodland caribou during summer–autumn. J Wildl Manage 2022. [DOI: 10.1002/jwmg.22161] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Kristin Denryter
- Natural Resources and Environmental Studies University of Northern British Columbia 3333 University Way Prince George V2N 4Z9 BC Canada
| | - Rachel C. Cook
- National Council for Air and Stream Improvement, Forestry and Range Sciences Laboratory 1401 Gekeler Lane La Grande 97850 OR USA
| | - John G. Cook
- National Council for Air and Stream Improvement, Forestry and Range Sciences Laboratory 1401 Gekeler Lane La Grande 97850 OR USA
| | - Katherine L. Parker
- Natural Resources and Environmental Studies University of Northern British Columbia 3333 University Way Prince George V2N 4Z9 BC Canada
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Cook JG, Kelly AP, Cook RC, Culling B, Culling D, McLaren A, Larter NC, Watters M. Seasonal patterns in nutritional condition of caribou (Rangifer tarandus) in the southern Northwest Territories and northeastern British Columbia, Canada. CAN J ZOOL 2021. [DOI: 10.1139/cjz-2021-0057] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Evaluating nutritional condition provides insights of nutritional influences on wildlife populations. We sampled three measures of condition — body fat, body mass, and loin thickness — of adult female caribou (Rangifer tarandus (Linnaeus, 1758)) in boreal settings in the Northwest Territories (NT), Canada, in December and March, 2016–2018, and in mountain and boreal settings in British Columbia (BC), Canada, in December and February, 2014–2015. We evaluated the effect of calf-rearing on condition in December, compared influences of summer–autumn versus winter on condition over winter, and developed an annual profile of nutritional condition with estimates from caribou dying in summer. Mean December body fat was 8.4% in females with calves and 11.4% in females without calves, demonstrating the influence of lactation on condition. Over winter, nutritional condition did not decline in northeastern BC and it declined slightly in NT: body fat by 0.55 percentage points, mass by 2.8 kg, and loin thickness did not change. Body fat peaked in December, changed little over winter, but declined to a minimum by early summer, temporally coinciding with elevated rates of adult female mortality. Consistent with those of other ungulate studies worldwide, our findings suggest a need to focus on nutritional limitations operating in late spring through early autumn.
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Affiliation(s)
- John G. Cook
- Forestry and Range Sciences Laboratory, National Council for Air and Stream Improvement, 1401 Gekeler Lane, La Grande, OR 1401 Gekeler Lane, USA
| | - Allicia P. Kelly
- Department of Environment and Natural Resources, Government of the Northwest Territories, Box 900, Fort Smith, NT X0E 0P0, Canada
| | - Rachel C. Cook
- Forestry and Range Sciences Laboratory, National Council for Air and Stream Improvement, 1401 Gekeler Lane, La Grande, OR 1401 Gekeler Lane, USA
| | - Brad Culling
- Diversified Environmental, Box 6263, Fort St. John, BC V1J 4X7, Canada
| | - Diane Culling
- Diversified Environmental, Box 6263, Fort St. John, BC V1J 4X7, Canada
| | - Ashley McLaren
- Wildlife Research and Monitoring Section, Ontario Ministry of Natural Resources and Forestry, Peterborough, ON K9L 1Z8, Canada
| | - Nicholas C. Larter
- Department of Environment and Natural Resources, Government of the Northwest Territories, Fort Simpson, NT X0E 0N0, Canada
| | - Megan Watters
- British Columbia Ministry of Forests, Lands, Natural Resource Operations and Rural Development, Fort St. John, BC V1J 6M7, Canada
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Variable strategies to solve risk-reward tradeoffs in carnivore communities. Proc Natl Acad Sci U S A 2021; 118:2101614118. [PMID: 34429359 DOI: 10.1073/pnas.2101614118] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mesopredator release theory suggests that dominant predators suppress subordinate carnivores and ultimately shape community dynamics, but the assumption that subordinate species are only negatively affected ignores the possibility of facilitation through scavenging. We examined the interplay within a carnivore community consisting of cougars, coyotes, black bears, and bobcats using contemporaneous Global Positioning System telemetry data from 51 individuals; diet analysis from 972 DNA-metabarcoded scats; and data from 128 physical investigations of cougar kill sites, 28 of which were monitored with remote cameras. Resource provisioning from competitively dominant cougars to coyotes through scavenging was so prolific as to be an overwhelming determinant of coyote behavior, space use, and resource acquisition. This was evident via the strong attraction of coyotes to cougar kill sites, frequent scavenging of cougar-killed prey, and coyote diets that nearly matched cougars in the magnitude of ungulate consumption. Yet coyotes were often killed by cougars and used space to minimize encounters, complicating the fitness benefits gained from scavenging. We estimated that 23% (95% CI: 8 to 55%) of the coyote population in our study area was killed by cougars annually, suggesting that coyote interactions with cougars are a complex behavioral game of risk and reward. In contrast, we found no indication that bobcat space use or diet was influenced by cougars. Black bears avoided cougars, but there was no evidence of attraction to cougar kill sites and much lower levels of ungulate consumption and carcass visitation than for coyotes. Interspecific interactions among carnivores are multifaceted, encompassing both suppression and facilitation.
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10
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Cook RC, Crouse JA, Cook JG, Stephenson TR. Evaluating indices of nutritional condition for caribou (Rangifer tarandus): which are the most valuable and why? CAN J ZOOL 2021. [DOI: 10.1139/cjz-2020-0149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Body composition studies are critical for evaluating the accuracy of nutritional condition indices for predicting body components. We evaluated >40 indices of nutritional condition for caribou (Rangifer tarandus (Linnaeus, 1758)) using 29 female caribou captured from three populations in Alaska (USA) that ranged in condition from 2.3% to 11.2% ingesta-free body fat (IFBF) and 6 captive female caribou that ranged in condition from 8.1% to 26.0% IFBF. Estimates of body fat, protein, and gross energy were regressed against each index of nutritional condition. Generally, indices with linear or slightly curvilinear relations to body fat and those based on multiple fat depots were the most accurate in predicting nutritional condition and the most useful over the full range of nutritional condition. A scaledLIVINDEX (a combination of subcutaneous fat thickness and a condition score), CONINDEX (a combination of kidney fat and marrow fat), and a subset of the Kistner score (pericardium and kidneys only) had the strongest relationship with body fat (r2 > 0.86) and were useful over the entire range of nutritional condition. If used properly and with adequate training, indices of nutritional condition can be a critical tool for understanding the severity and seasonality of nutritional limitations in wild caribou populations.
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Affiliation(s)
- Rachel C. Cook
- National Council for Air and Stream Improvement, Forestry and Range Sciences Laboratory, 1401 Gekeler Lane, La Grande, OR 97850, USA
| | - John A. Crouse
- Kenai Moose Research Center, Alaska Department of Fish and Game, 43961 Kalifornsky Beach Road, Suite B, Soldotna, AK 99669, USA
| | - John G. Cook
- National Council for Air and Stream Improvement, Forestry and Range Sciences Laboratory, 1401 Gekeler Lane, La Grande, OR 97850, USA
| | - Thomas R. Stephenson
- Sierra Nevada Bighorn Sheep Recovery Program, California Department of Fish and Wildlife, 787 North Main Street, Suite 220, Bishop, CA 93514, USA
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11
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Sergeyev M, McMillan BR, Hersey KR, Larsen RT. How Size and Condition Influence Survival and Cause‐Specific Mortality of Female Elk. J Wildl Manage 2021. [DOI: 10.1002/jwmg.22000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Maksim Sergeyev
- Department of Plant and Wildlife Sciences Brigham Young University Provo UT 84604 USA
| | - Brock R. McMillan
- Department of Plant and Wildlife Sciences Brigham Young University Provo UT 84604 USA
| | - Kent R. Hersey
- Utah Division of Wildlife Resources Salt Lake City UT 84116 USA
| | - Randy T. Larsen
- Department of Plant and Wildlife Sciences Brigham Young University Provo UT 84604 USA
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12
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Proffitt KM, Garrott R, Gude JA, Hebblewhite M, Jimenez B, Paterson JT, Rotella J. Integrated Carnivore‐Ungulate Management: A Case Study in West‐Central Montana. WILDLIFE MONOGRAPHS 2020. [DOI: 10.1002/wmon.1056] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Kelly M. Proffitt
- Montana Department of Fish Wildlife and Parks 1400 South 19th Street Bozeman MT 59718 USA
| | - Robert Garrott
- Department of Ecology, Fish and Wildlife Ecology and Management Program Montana State University 310 Lewis Hall Bozeman MT 59718 USA
| | - Justin A. Gude
- Montana Department of Fish Wildlife and Parks 1420 E 6th Ave Helena MT 59620 USA
| | - Mark Hebblewhite
- Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and Conservation University of Montana Missoula MT 59812 USA
| | - Benjamin Jimenez
- Montana Department of Fish Wildlife and Parks 3201 Spurgin Road Missoula MT 59804 USA
| | - J. Terrill Paterson
- Department of Ecology Montana State University 310 Lewis Hall Bozeman MT 59718 USA
| | - Jay Rotella
- Department of Ecology Montana State University 310 Lewis Hall Bozeman MT 59718 USA
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13
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Walker PD, Rodgers AR, Shuter JL, Thompson ID, Fryxell JM, Cook JG, Cook RC, Merrill EH. Comparison of Woodland Caribou Calving Areas Determined by Movement Patterns Across Northern Ontario. J Wildl Manage 2020. [DOI: 10.1002/jwmg.21961] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Philip D. Walker
- Department of Biological Sciences University of Alberta Edmonton AB T6G 2E9 Canada
| | - Arthur R. Rodgers
- Ontario Ministry of Natural Resources and Forestry Centre for Northern Forest Ecosystem Research 103‐421 James Street South Thunder Bay ON P7E 2V6 Canada
| | - Jennifer L. Shuter
- Ontario Ministry of Natural Resources and Forestry Centre for Northern Forest Ecosystem Research 103‐421 James Street South Thunder Bay ON P7E 2V6 Canada
| | - Ian D. Thompson
- Canadian Forest Service (Retired) 1219 Queen Street E, Sault Ste. Marie ON P6A 2E5 Canada
| | - John M. Fryxell
- Department of Integrative Biology University of Guelph Guelph ON N1G 2W1 Canada
| | - John G. Cook
- National Council for Air and Stream Improvement Forestry and Range Science Laboratory 1401 Gekeler Lane La Grande OR 97850 USA
| | - Rachel C. Cook
- National Council for Air and Stream Improvement Forestry and Range Science Laboratory 1401 Gekeler Lane La Grande OR 97850 USA
| | - Eveyln H. Merrill
- Department of Biological Sciences University of Alberta Edmonton AB T6G 2E9 Canada
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14
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Stephenson TR, German DW, Cassirer EF, Walsh DP, Blum ME, Cox M, Stewart KM, Monteith KL. Linking population performance to nutritional condition in an alpine ungulate. J Mammal 2020; 101:1244-1256. [PMID: 33335453 PMCID: PMC7733374 DOI: 10.1093/jmammal/gyaa091] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 07/10/2020] [Indexed: 11/14/2022] Open
Abstract
Bighorn sheep (Ovis canadensis) can live in extremely harsh environments and subsist on submaintenance diets for much of the year. Under these conditions, energy stored as body fat serves as an essential reserve for supplementing dietary intake to meet metabolic demands of survival and reproduction. We developed equations to predict ingesta-free body fat in bighorn sheep using ultrasonography and condition scores in vivo and carcass measurements postmortem. We then used in vivo equations to investigate the relationships between body fat, pregnancy, overwinter survival, and population growth in free-ranging bighorn sheep in California and Nevada. Among 11 subpopulations that included alpine winter residents and migrants, mean ingesta-free body fat of lactating adult females during autumn ranged between 8.8% and 15.0%; mean body fat for nonlactating females ranged from 16.4% to 20.9%. In adult females, ingesta-free body fat > 7.7% during January (early in the second trimester) corresponded with a > 90% probability of pregnancy and ingesta-free body fat > 13.5% during autumn yielded a probability of overwinter survival > 90%. Mean ingesta-free body fat of lactating females in autumn was positively associated with finite rate of population increase (λ) over the subsequent year in bighorn sheep subpopulations that wintered in alpine landscapes. Bighorn sheep with ingesta-free body fat of 26% in autumn and living in alpine environments possess energy reserves sufficient to meet resting metabolism for 83 days on fat reserves alone. We demonstrated that nutritional condition can be a pervasive mechanism underlying demography in bighorn sheep and characterizes the nutritional value of their occupied ranges. Mountain sheep are capital survivors in addition to being capital breeders, and because they inhabit landscapes with extreme seasonal forage scarcity, they also can be fat reserve obligates. Quantifying nutritional condition is essential for understanding the quality of habitats, how it underpins demography, and the proximity of a population to a nutritional threshold.
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Affiliation(s)
- Thomas R Stephenson
- Sierra Nevada Bighorn Sheep Recovery Program, California Department of Fish and Wildlife, Bishop, CA, USA
| | - David W German
- Sierra Nevada Bighorn Sheep Recovery Program, California Department of Fish and Wildlife, Bishop, CA, USA
| | | | | | - Marcus E Blum
- Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV, USA
| | - Mike Cox
- Nevada Department of Wildlife, Reno, NV, USA
| | - Kelley M Stewart
- Department of Natural Resources and Environmental Science, University of Nevada, Reno, NV, USA
| | - Kevin L Monteith
- Haub School of the Environment, Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA (KLM)
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15
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Weckerly FW. Frequency and Density Associated Grouping Patterns of Male Roosevelt Elk. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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16
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Logan KA. Puma population limitation and regulation: What matters in puma management? J Wildl Manage 2019. [DOI: 10.1002/jwmg.21753] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Kenneth A. Logan
- Colorado Parks and Wildlife 2300 S. Townsend Avenue Montrose CO 81401 USA
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17
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Clark DA, Coe PK, Gregory SC, Hedrick MJ, Johnson BK, Jackson DH. Habitat Use Informs Species Needs and Management: A Reply to Maestas et al. J Wildl Manage 2019. [DOI: 10.1002/jwmg.21671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Darren A. Clark
- Oregon Department of Fish and Wildlife 1401 Gekeler Lane La Grande OR 97850 USA
| | - Priscilla K. Coe
- Oregon Department of Fish and Wildlife 1401 Gekeler Lane La Grande OR 97850 USA
| | - Sara C. Gregory
- Oregon Department of Fish and Wildlife 61374 Parrell Road Bend OR 97702 USA
| | - Mary Jo Hedrick
- Oregon Department of Fish and Wildlife 53447 Highway 31 Summer Lake OR 97640 USA
| | - Bruce K. Johnson
- Oregon Department of Fish and Wildlife 1401 Gekeler Lane La Grande OR 97850 USA
| | - DeWaine H. Jackson
- Oregon Department of Fish and Wildlife 4192 N Umpqua Highway Roseburg OR 97470 USA
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