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Dori P, Anastasio I, Macchi E, Manenti I, Hones M, Carosi M. Hibernating or not hibernating? Brown bears' response to a mismatch between environmental natural cues and captive management, and its welfare implications. PLoS One 2024; 19:e0306537. [PMID: 39083476 PMCID: PMC11290645 DOI: 10.1371/journal.pone.0306537] [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: 01/25/2024] [Accepted: 06/19/2024] [Indexed: 08/02/2024] Open
Abstract
In wild brown bears, likely factors triggering hibernation response to harsh environmental conditions are temperature, photoperiod, and food resources availability. In fact, constantly fed captive brown bears are described as skipping hibernation being active all year-round. Is the hibernation response so flexible and subordinate to contingencies, or else is an adaptation that, if dismissed, may negatively impact on bear well-being? This study investigates the potential hibernation response in captive brown bears under unvaried management conditions using an integrative approach simultaneously analyzing multiple animal-based variables together with environmental covariates. Data from a mid-latitude zoo revealed distinct behavioral, fecal glucocorticoids, and body condition score seasonal fluctuations, resembling natural hibernation cycles, despite constant food access. Environmental variables like photoperiod and visitor numbers significantly influenced activity levels. Bears exhibited behaviors indicative of hyperphagia and fall transition, such as appetitive feeding and denning behaviors. Hormonal analyses revealed high fecal cortisol metabolites levels during hyperphagia, suggesting physiological responses to seasonal changes. Findings underscore the importance of environmental cues and food availability in shaping zoo bear behavior and physiology. Considering that the hibernating vs. non-hibernating description might represent an oversimplification, management strategies should deal with captive bear potential need to freely express their adaptive predispositions by accommodating their natural behaviors, such as providing denning spots and adjusting diet composition as soon as typical hyperphagic and predenning behaviors emerge, ultimately enhancing their well-being.
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Affiliation(s)
- Paolo Dori
- Department of Science, Roma Tre University, Rome, Italy
| | | | | | - Isabella Manenti
- Department of Veterinary Science, University of Turin, Turin, Italy
| | | | - Monica Carosi
- Department of Science, Roma Tre University, Rome, Italy
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2
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Schulte L, De Angelis D, Babic N, Reljić S. Very Small Home Ranges of Two Gravid European Brown Bears during Hyperphagia. Animals (Basel) 2021; 11:3580. [PMID: 34944355 PMCID: PMC8697980 DOI: 10.3390/ani11123580] [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: 10/20/2021] [Revised: 12/06/2021] [Accepted: 12/13/2021] [Indexed: 11/16/2022] Open
Abstract
In September 2019, two gravid female brown bears (Ursus arctos) were captured and equipped with GPS/GSM collars in Paklenica National Park (Croatia). Home ranges during hyperphagia were analyzed to describe the spatiotemporal requirements. Mean seasonal home ranges were very small with 9.2 km2 and 7.5 km2 (Brownian Bridge Movement Model 95%). During the tracking period, both bears used different territories and showed little to no use of overlapping area. The bears in our study spent a considerable time in proximity of artificial feeding sites, indicating a probable use of these structures as a food resource (mean 15.7% and 30.7%). Furthermore, the bears approached very close to human structures such as 8.9 m and 4.4 m. As most encounters between humans and bears occur during hyperphagia, it is important to offer refugia from human disturbance, especially as the National Park is not only used by residents, but also by tourists. To adapt management according to the animal's needs, further studies should include more individuals from different age and sex classes. Both females were gravid. It remains unclear whether gravidity has an effect on the home range and should be further investigated.
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Affiliation(s)
- Laura Schulte
- Department of Behavioural Ecology, Bielefeld University, 33615 Bielefeld, Germany
| | - Daniele De Angelis
- Department of Biology and Biotechnology “Charles Darwin” BBCD, Sapienza University of Rome, 00185 Rome, Italy;
| | - Natarsha Babic
- School of Biological Sciences, Clayton Campus, Monash University, Melbourne, VIC 3800, Australia;
| | - Slaven Reljić
- Biology Department, Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia;
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3
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Finnegan SP, Svoboda NJ, Fowler NL, Schooler SL, Belant JL. Variable intraspecific space use supports optimality in an apex predator. Sci Rep 2021; 11:21115. [PMID: 34702922 PMCID: PMC8548348 DOI: 10.1038/s41598-021-00667-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 10/11/2021] [Indexed: 11/10/2022] Open
Abstract
Within optimality theory, an animal's home range can be considered a fitness-driven attempt to obtain resources for survival and reproduction while minimizing costs. We assessed whether brown bears (Ursus arctos) in two island populations maximized resource patches within home ranges (Resource Dispersion Hypothesis [RDH]) or occupied only areas necessary to meet their biological requirements (Temporal Resource Variability Hypothesis [TRVH]) at annual and seasonal scales. We further examined how intrinsic factors (age, reproductive status) affected optimal choices. We found dynamic patterns of space use between populations, with support for RDH and TRVH at both scales. The RDH was likely supported seasonally as a result of bears maximizing space use to obtain a mix of nutritional resources for weight gain. Annually, support for RDH likely reflected changing abundances and distributions of foods within different timber stand classes. TRVH was supported at both scales, with bears minimizing space use when food resources were temporally concentrated. Range sizes and optimal strategies varied among sex and reproductive classes, with males occupying larger ranges, supporting mate seeking behavior and increased metabolic demands of larger body sizes. This work emphasizes the importance of scale when examining animal movement ecology, as optimal behavioral decisions are scale dependent.
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Affiliation(s)
- S P Finnegan
- Global Wildlife Conservation Center, State University of New York College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY, 13204, USA.
| | - N J Svoboda
- Alaska Department of Fish and Game, Kodiak, AK, USA
| | - N L Fowler
- Global Wildlife Conservation Center, State University of New York College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY, 13204, USA
- Alaska Department of Fish and Game, Soldotna, AK, USA
| | - S L Schooler
- Global Wildlife Conservation Center, State University of New York College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY, 13204, USA
| | - J L Belant
- Global Wildlife Conservation Center, State University of New York College of Environmental Science and Forestry, 1 Forestry Drive, Syracuse, NY, 13204, USA
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4
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Fowler NL, Spady TJ, Wang G, Leopold BD, Belant JL. Denning, metabolic suppression, and the realisation of ecological opportunities in Ursidae. Mamm Rev 2021. [DOI: 10.1111/mam.12246] [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]
Affiliation(s)
- Nicholas L. Fowler
- Global Wildlife Conservation Center State University of New York College of Environmental Science and Forestry 1 Forestry Drive Syracuse NY13210USA
| | - Thomas J. Spady
- Department of Biological Sciences California State University San Marcos San Marcos CA92096USA
| | - Guiming Wang
- Department of Wildlife, Fisheries, and Aquaculture Mississippi State UniversityMississippi State Box 9690MS39762USA
| | - Bruce D. Leopold
- Department of Wildlife, Fisheries, and Aquaculture Mississippi State UniversityMississippi State Box 9690MS39762USA
| | - Jerrold L. Belant
- Global Wildlife Conservation Center State University of New York College of Environmental Science and Forestry 1 Forestry Drive Syracuse NY13210USA
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Stable Isotopes Reveal Variation in Consumption of Pacific Salmon by Brown Bears, Despite Ready Access in Small Streams. JOURNAL OF FISH AND WILDLIFE MANAGEMENT 2020. [DOI: 10.3996/jfwm-20-034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Abstract
Brown bears Ursus arctos consume a wide range of organisms, including ungulates and plants, but Pacific salmon Oncorhynchus spp. are especially important to their diet where their ranges overlap. Although some brown bears minimize antagonistic encounters with other brown bears or infanticide by avoiding streams where salmon spawn, studies generally assume that brown bears with ready access to salmon feed heavily on them. To test this assumption, and the hypothesis that male brown bears would feed more heavily on salmon than females (owing to their sexual size dimorphism), we collected hair samples from brown bears by using barbed wire placed on six small tributaries of Lake Aleknagik, Alaska, USA, where adult Sockeye Salmon Oncorhynchus nerka are readily accessible and frequently consumed by brown bears. Analysis of DNA distinguished among the different brown bears leaving the hair samples, some of which were sampled multiple times within and among years. We assessed the contribution of salmon to the diet of individual brown bears by using carbon and nitrogen stable isotope signatures. The 77 samples analyzed from 31 different bears over 4 y showed isotopic ratios consistent with reliance on salmon, but the wide range of isotopic signatures included values suggesting variable, and in one case considerable, use of terrestrial resources. Stable isotope signatures did not differ between male and female brown bears, nor did they differ between two sides of the lake, despite marked differences in Sockeye Salmon density. We collected the hair samples when salmon were present, so there was some uncertainty regarding whether they reflected feeding during the current or previous season. Notwithstanding this caveat, the results are consistent with the hypothesis that salmon were sufficiently available to provide food for the brown bears and that the considerable isotopic variation among brown bears with access to salmon reflected their age, status, and behavior.
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Rogers MC, Hilderbrand GV, Gustine DD, Joly K, Leacock WB, Mangipane BA, Welker JM. Splitting hairs: dietary niche breadth modelling using stable isotope analysis of a sequentially grown tissue. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 2020; 56:358-369. [PMID: 32631088 DOI: 10.1080/10256016.2020.1787404] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 05/23/2020] [Indexed: 06/11/2023]
Abstract
Stable isotope data from durable, sequentially grown tissues (e.g. hair, claw, and baleen) is commonly used for modelling dietary niche breadth. The use of tissues grown over multiple months to years, however, has the potential to complicate isotopic niche breadth modelling, as time-averaged stable isotope signals from whole tissues may obscure information available from chronologically resolved stable isotope signals in serially sectioned tissues. We determined if whole samples of brown bear guard hair produced different isotopic niche breadth estimates than those produced from subsampled, serially sectioned samples of the same tissue from the same set of individuals. We sampled guard hair from brown bears (Ursus arctos) in four regions of Alaska with disparate biogeographies and dietary resource availability. Whole hair and serially sectioned hair samples were used to produce paired isotopic dietary niche breadth estimates for each region in the SIBER Bayesian model framework in R. Isotopic data from serially sectioned hair consistently produced larger estimates of isotopic dietary niche breadth than isotope data from whole hair samples. Serial sampling captures finer-scale changes in diet and when cumulatively used to estimate isotopic niche breadth, the serially sampled isotope data more fully captures dietary variability and true isotopic niche breadth.
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Affiliation(s)
- Matthew C Rogers
- Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA
- NOAA Alaska Fisheries Science Center, Auke Bay Laboratories, Juneau, AK, USA
| | | | - David D Gustine
- National Park Service, Grand Teton National Park, Moose, WY, USA
| | - Kyle Joly
- National Park Service, Gates of the Arctic National Park and Preserve, Fairbanks, AK, USA
| | - William B Leacock
- US Fish and Wildlife Service, Kodiak National Wildlife Refuge, Kodiak, AK, USA
| | - Buck A Mangipane
- National Park Service, Lake Clark National Park and Preserve, Port Alsworth, AK, USA
| | - Jeffrey M Welker
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, USA
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Mangipane LS, Lafferty DJR, Joly K, Sorum MS, Cameron MD, Belant JL, Hilderbrand GV, Gustine DD. Dietary plasticity and the importance of salmon to brown bear (Ursus arctos) body size and condition in a low Arctic ecosystem. Polar Biol 2020. [DOI: 10.1007/s00300-020-02690-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
AbstractEcological flexibility within animal populations can allow for variation in resource use and foraging decisions. We estimated brown bear (Ursus arctos) diet composition in Gates of the Arctic National Park and Preserve, Alaska from 2013 to 2015 to evaluate how variation in foraging behavior influences body condition and size. We used stable carbon (δ13C) and nitrogen (δ15N) isotope analyses of sectioned brown bear hair samples to evaluate assimilated diet. We then developed a set of a priori linear models to evaluate differences in the diet composition of brown bears (n = 80) in relation to body fat (%) and mass. The proportion of meat (salmon [Oncorhynchus keta] and terrestrial meat combined) in the diet from July through late September varied between male and female bears, with males ($$\stackrel{-}{x}$$
x
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= 62%, SD = 30) assimilating significantly more meat than females ($$\stackrel{-}{x}$$
x
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= 40%, SD = 29). Most of the meat consumed came from marine-derived resources for males (53% of the total diet or 86% of the meat) and females (31% of the total diet or 77% of the meat). As we found the range of observed diets was unrelated to physiological outcomes (i.e., percentage body fat), we suggest that ecological flexibility within populations may provide an adaptive advantage by allowing individuals to reduce competition with conspecifics by foraging on alternate food resources. Identifying variable foraging behaviors within a population can allow for a better understanding of complex behaviors and, ultimately, lead to more informed management decisions related to habitat use, development, and harvest.
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Fowler NL, Belant JL, Wang G, Leopold BD. Ecological plasticity of denning chronology by American black bears and brown bears. Glob Ecol Conserv 2019. [DOI: 10.1016/j.gecco.2019.e00750] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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9
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Mangipane LS, Belant JL, Lafferty DJR, Gustine DD, Hiller TL, Colvin ME, Mangipane BA, Hilderbrand GV. Dietary plasticity in a nutrient-rich system does not influence brown bear (Ursus arctos) body condition or denning. Polar Biol 2017. [DOI: 10.1007/s00300-017-2237-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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10
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Bled F, Belant JL, Van Daele LJ, Svoboda N, Gustine D, Hilderbrand G, Barnes VG. Using multiple data types and integrated population models to improve our knowledge of apex predator population dynamics. Ecol Evol 2017; 7:9531-9543. [PMID: 29187987 PMCID: PMC5696435 DOI: 10.1002/ece3.3469] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 07/28/2017] [Accepted: 09/01/2017] [Indexed: 11/10/2022] Open
Abstract
Current management of large carnivores is informed using a variety of parameters, methods, and metrics; however, these data are typically considered independently. Sharing information among data types based on the underlying ecological, and recognizing observation biases, can improve estimation of individual and global parameters. We present a general integrated population model (IPM), specifically designed for brown bears (Ursus arctos), using three common data types for bear (U. spp.) populations: repeated counts, capture–mark–recapture, and litter size. We considered factors affecting ecological and observation processes for these data. We assessed the practicality of this approach on a simulated population and compared estimates from our model to values used for simulation and results from count data only. We then present a practical application of this general approach adapted to the constraints of a case study using historical data available for brown bears on Kodiak Island, Alaska, USA. The IPM provided more accurate and precise estimates than models accounting for repeated count data only, with credible intervals including the true population 94% and 5% of the time, respectively. For the Kodiak population, we estimated annual average litter size (within one year after birth) to vary between 0.45 [95% credible interval: 0.43; 0.55] and 1.59 [1.55; 1.82]. We detected a positive relationship between salmon availability and adult survival, with survival probabilities greater for females than males. Survival probabilities increased from cubs to yearlings to dependent young ≥2 years old and decreased with litter size. Linking multiple information sources based on ecological and observation mechanisms can provide more accurate and precise estimates, to better inform management. IPMs can also reduce data collection efforts by sharing information among agencies and management units. Our approach responds to an increasing need in bear populations’ management and can be readily adapted to other large carnivores.
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Affiliation(s)
- Florent Bled
- Carnivore Ecology Laboratory Mississippi State University Mississippi State MS USA
| | - Jerrold L Belant
- Carnivore Ecology Laboratory Mississippi State University Mississippi State MS USA
| | | | | | - David Gustine
- United States Geological Survey Alaska Science Center Anchorage AK USA.,Grand Teton National Park National Park Service Moose WY USA
| | - Grant Hilderbrand
- United States Geological Survey Alaska Science Center Anchorage AK USA.,National Park Service Alaska Regional Office Anchorage AK USA
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11
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Gormezano LJ, Ellis-Felege SN, Iles DT, Barnas A, Rockwell RF. Polar Bear Foraging Behavior During the Ice-Free Period in Western Hudson Bay: Observations, Origins, and Potential Significance. AMERICAN MUSEUM NOVITATES 2017. [DOI: 10.1206/3885.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Linda J. Gormezano
- Division of Vertebrate Zoology, American Museum of Natural History, New York
| | | | - David T. Iles
- Department of Biology, Tufts University, Medford, MA
| | - Andrew Barnas
- Department of Biology, University of North Dakota, Grand Forks, ND
| | - Robert F. Rockwell
- Division of Vertebrate Zoology, American Museum of Natural History, New York
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12
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Stenset NE, Lutnæs PN, Bjarnadóttir V, Dahle B, Fossum KH, Jigsved P, Johansen T, Neumann W, Opseth O, Rønning O, Steyaert SMJG, Zedrosser A, Brunberg S, Swenson JE. Seasonal and annual variation in the diet of brown bearsUrsus arctosin the boreal forest of southcentral Sweden. WILDLIFE BIOLOGY 2016. [DOI: 10.2981/wlb.00194] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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13
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Fox CH, Paquet PC, Reimchen TE. Novel species interactions: American black bears respond to Pacific herring spawn. BMC Ecol 2015; 15:14. [PMID: 26013706 PMCID: PMC4445564 DOI: 10.1186/s12898-015-0045-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 04/22/2015] [Indexed: 11/10/2022] Open
Abstract
Background In addition to the decline and extinction of the world’s species, the decline and eventual loss of species interactions is one of the major consequences of the biodiversity crisis. On the Pacific coast of North America, diminished runs of salmon (Oncorhynchus spp.) drive numerous marine–terrestrial interactions, many of which have been intensively studied, but marine–terrestrial interactions driven by other species remain relatively unknown. Bears (Ursus spp.) are major vectors of salmon into terrestrial ecosystems, but their participation in other cross-ecosystem interactions is similarly poorly described. Pacific herring (Clupea pallasii), a migratory forage fish in coastal marine ecosystems of the North Pacific Ocean and the dominant forage fish in British Columbia (BC), spawn in nearshore subtidal and intertidal zones. Spawn resources (eggs, milt, and spawning adults) at these events are available to coastal predators and scavengers, including terrestrial species. In this study, we investigated the interaction between American black bears (Ursus americanus) and Pacific herring at spawn events in Quatsino Sound, BC, Canada. Results Using remote cameras to monitor bear activity (1,467 camera days, 29 sites, years 2010–2012) in supratidal and intertidal zones and a machine learning approach, we determined that the quantity of Pacific herring eggs in supratidal and intertidal zones was a leading predictor of black bear activity, with bears positively responding to increasing herring egg masses. Other important predictors included day of the year and Talitrid amphipod (Traskorchestia spp.) mass. A complementary analysis of black bear scats indicated that Pacific herring egg mass was the highest ranked predictor of egg consumption by bears. Pacific herring eggs constituted a substantial yet variable component of the early springtime diet of black bears in Quatsino Sound (frequency of occurrence 0–34%; estimated dietary content 0–63%). Other major dietary items included graminoids (grasses and sedges), Phaeophyta (brown algae), Zosteraceae (seagrasses), and Talitrid amphipods. Conclusion This research represents the first scientific evidence of a cross-ecosystem interaction between Pacific herring and American black bears. Our findings also expand knowledge of the ecological roles of both species. Combined, evidence of anthropogenic constraints on both black bears and Pacific herring suggests that bear-herring interactions were potentially stronger and more widespread in the past.
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Affiliation(s)
- Caroline Hazel Fox
- Raincoast Conservation Foundation, PO Box 2429, Sidney, BC, V8L 3Y3, Canada. .,Department of Biology, University of Victoria, PO Box 1700 STN CSC, Victoria, BC, V8W 2Y2, Canada. .,Department of Geography, University of Victoria, PO Box 1700 STN CSC, Victoria, BC, V8W 2Y2, Canada.
| | - Paul Charles Paquet
- Raincoast Conservation Foundation, PO Box 2429, Sidney, BC, V8L 3Y3, Canada. .,Department of Geography, University of Victoria, PO Box 1700 STN CSC, Victoria, BC, V8W 2Y2, Canada.
| | - Thomas Edward Reimchen
- Department of Biology, University of Victoria, PO Box 1700 STN CSC, Victoria, BC, V8W 2Y2, Canada.
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Barber-Meyer SM. Trophic cascades from wolves to grizzly bears or changing abundance of bears and alternate foods? J Anim Ecol 2015; 84:647-651. [PMID: 25732302 DOI: 10.1111/1365-2656.12338] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 09/23/2014] [Indexed: 11/29/2022]
Abstract
This is a Forum article commenting on: Ripple, W. J., Beschta, R. L., Fortin, J. K., & Robbins, C. T. (2014) Trophic cascades from wolves to grizzly bears in Yellowstone. Journal of Animal Ecology, 83, 223-233. Comparisons Ripple et al. (2014) used to demonstrate increased fruit availability and consumption by grizzly bears post-wolf reintroduction are flawed and tenuous at best. Importantly, a more parsimonious (than trophic cascades) hypothesis, not sufficiently considered by Ripple et al., exists and is better supported by available data I review.
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Affiliation(s)
- Shannon M Barber-Meyer
- U.S. Geological Survey, Northern Prairie Wildlife Research Center, 8711 - 37th St., SE, Jamestown, ND, 58401-7317, USA
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15
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Barker OE, Derocher AE, Edwards MA. Use of Arctic ground squirrels (Urocitellus parryii) by brown bears (Ursus arctos). Polar Biol 2014. [DOI: 10.1007/s00300-014-1593-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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16
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Gunther KA, Shoemaker RR, Frey KL, Haroldson MA, Cain SL, van Manen FT, Fortin JK. Dietary breadth of grizzly bears in the Greater Yellowstone Ecosystem. URSUS 2014. [DOI: 10.2192/ursus-d-13-00008.1] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Kerry A. Gunther
- Bear Management Office, Yellowstone Center for Resources, Yellowstone National Park, P.O. Box 168, Yellowstone National Park, WY 82190, USA
| | - Rebecca R. Shoemaker
- Grizzly Bear Recovery Office, U.S. Fish and Wildlife Service, Missoula, MT 59812, USA
| | - Kevin L. Frey
- Bear Management Office, Montana Fish, Wildlife, and Parks, 1400 South 19th Avenue, Bozeman, MT 59718, USA
| | - Mark A. Haroldson
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Interagency Grizzly Bear Study Team, 2327 University Way, Suite 2, Bozeman, MT 59715, USA
| | - Steven L. Cain
- Grand Teton National Park, P.O. Box 170, Moose, WY 83012, USA
| | - Frank T. van Manen
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Interagency Grizzly Bear Study Team, 2327 University Way, Suite 2, Bozeman, MT 59715, USA
| | - Jennifer K. Fortin
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
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17
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Costello CM, van Manen FT, Haroldson MA, Ebinger MR, Cain SL, Gunther KA, Bjornlie DD. Influence of whitebark pine decline on fall habitat use and movements of grizzly bears in the Greater Yellowstone Ecosystem. Ecol Evol 2014; 4:2004-18. [PMID: 24963393 PMCID: PMC4063492 DOI: 10.1002/ece3.1082] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 03/27/2014] [Accepted: 03/29/2014] [Indexed: 11/05/2022] Open
Abstract
When abundant, seeds of the high-elevation whitebark pine (WBP; Pinus albicaulis) are an important fall food for grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem. Rates of bear mortality and bear/human conflicts have been inversely associated with WBP productivity. Recently, mountain pine beetles (Dendroctonus ponderosae) have killed many cone-producing WBP trees. We used fall (15 August–30 September) Global Positioning System locations from 89 bear years to investigate temporal changes in habitat use and movements during 2000–2011. We calculated Manly–Chesson (MC) indices for selectivity of WBP habitat and secure habitat (≥500 m from roads and human developments), determined dates of WBP use, and documented net daily movement distances and activity radii. To evaluate temporal trends, we used regression, model selection, and candidate model sets consisting of annual WBP production, sex, and year. One-third of sampled grizzly bears had fall ranges with little or no mapped WBP habitat. Most other bears (72%) had a MC index above 0.5, indicating selection for WBP habitats. From 2000 to 2011, mean MC index decreased and median date of WBP use shifted about 1 week later. We detected no trends in movement indices over time. Outside of national parks, there was no correlation between the MC indices for WBP habitat and secure habitat, and most bears (78%) selected for secure habitat. Nonetheless, mean MC index for secure habitat decreased over the study period during years of good WBP productivity. The wide diet breadth and foraging plasticity of grizzly bears likely allowed them to adjust to declining WBP. Bears reduced use of WBP stands without increasing movement rates, suggesting they obtained alternative fall foods within their local surroundings. However, the reduction in mortality risk historically associated with use of secure, high-elevation WBP habitat may be diminishing for bears residing in multiple-use areas.
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Affiliation(s)
- Cecily M Costello
- College of Forestry and Conservation, University of Montana Missoula, MT, 59812, USA
| | - Frank T van Manen
- Interagency Grizzly Bear Study Team, U.S. Geological Survey, Northern Rocky Mountain Science Center Bozeman, MT, 59715, USA
| | - Mark A Haroldson
- Interagency Grizzly Bear Study Team, U.S. Geological Survey, Northern Rocky Mountain Science Center Bozeman, MT, 59715, USA
| | - Michael R Ebinger
- College of Forestry and Conservation, University of Montana Missoula, MT, 59812, USA
| | | | - Kerry A Gunther
- Bear Management Office, Yellowstone Center for Resources Yellowstone National Park, WY, 82190, USA
| | - Daniel D Bjornlie
- Large Carnivore Section, Wyoming Game & Fish Department Lander, WY, 82520, USA
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Van Daele M, Robbins C, Semmens B, Ward E, Van Daele L, Leacock W. Salmon consumption by Kodiak brown bears (Ursus arctos middendorffi) with ecosystem management implications. CAN J ZOOL 2013. [DOI: 10.1139/cjz-2012-0221] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ecological role of large predators in North America continues to spark heated public debate. Although brown bears (Ursus arctos L., 1758) and the salmon (genus Oncorhynchus Suckley, 1861) they feed on have declined in many areas, the Kodiak archipelago is famous for large brown bears and abundant salmon. Salmon have generally been managed for maximum sustained yield in a fisheries sense, but those levels may be well below what is necessary for maximum ecosystem productivity. Consequently, we used stable isotopes and mercury accumulated in hair to estimate intake of salmon by Kodiak brown bears (Ursus arctos middendorffi Merriam, 1896). Salmon intake increased from subadult males (592 ± 325 kg·bear−1·year−1) to adult males (2788 ± 1929 kg·bear−1·year−1) and from subadult females (566 ± 360 kg·bear−1·year−1) to adult females (1364 ± 1261 kg·bear−1·year−1). Intake within each group increased 62% ± 23% as salmon escapement increased from ∼1 500 to ∼14 000 kg·bear−1·year−1. The estimated population of 2300 subadult and adult bears consumed 3.77 ± 0.16 million kg of salmon annually, a mass equal to ∼6% of the combined escapement and commercial harvest (57.6 million kg). Although bears consume a small portion of the total mass of adult salmon, perpetuation of dense populations of large bears requires ecosystem-based management of the meat resources and environments that produce such bears.
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Affiliation(s)
- M.B. Van Daele
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - C.T. Robbins
- School of the Environment and School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - B.X. Semmens
- National Marine Fisheries Service, Northwest Fisheries Science Center, 2725 Montlake Boulevard East, Seattle, WA 98112, USA
| | - E.J. Ward
- National Marine Fisheries Service, Northwest Fisheries Science Center, 2725 Montlake Boulevard East, Seattle, WA 98112, USA
| | - L.J. Van Daele
- Alaska Department of Fish and Game, 211 Mission Road, Kodiak, AK 99615, USA
| | - W.B. Leacock
- Kodiak National Wildlife Refuge, 1390 Buskin River Road, Kodiak, AK 99615, USA
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