1
|
Dittemore CM, Tyers DB, Weaver DK, Nunlist EA, Sowell BF, Peterson E, Peterson RKD. Using Stable Isotopes to Determine Natal Origin and Feeding Habits of the Army Cutworm Moth, Euxoa auxiliaris (Lepidoptera: Noctuidae). ENVIRONMENTAL ENTOMOLOGY 2023; 52:230-242. [PMID: 36801934 PMCID: PMC10112843 DOI: 10.1093/ee/nvad006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Indexed: 06/18/2023]
Abstract
The army cutworm, Euxoa auxiliaris (Grote), is a migratory noctuid that is both an agricultural pest and an important late-season food source for grizzly bears, Ursus arctos horribilis (Linnaeus, Carnivora: Ursidae), within the Greater Yellowstone Ecosystem. Beyond the confirmation of the moths' seasonal, elevational migration in the mid-1900s, little else has been documented about their migratory patterns. To address this missing ecological component, we examined (1) migratory routes during their spring and fall migratory periods throughout their natal range, the Great Plains, and (2) natal origin at two of their summering ranges using stable hydrogen (δ2H) analyses of wings from samples collected within the areas of interest. Stable carbon (δ13C) and stable nitrogen (δ15N) analyses of wings were used to evaluate larval feeding habits of the migrants and agricultural intensity of natal origin sites, respectively. Results suggest that, rather than migrating exclusively east to west, army cutworm moths are also migrating north to south during their spring migration. Moths did not exhibit natal origin site fidelity when returning to the Great Plains. Migrants collected from the Absaroka Range had the highest probability of natal origin in Alberta, British Columbia, Saskatchewan, the most southern region of the Northwest Territories, and second highest probability of origin in Montana, Wyoming, and Idaho. Migrants collected in the Lewis Range had the highest probability of origin in the same provinces of Canada. Results suggest that migrants of the Absaroka Range fed exclusively on C3 plants as larvae and rarely fed in heavily fertilized agroecosystems.
Collapse
Affiliation(s)
| | - Daniel B Tyers
- USDA Forest Service, Interagency Grizzly Bear Study Team, Northern Rockies Science Center, Bozeman, MT 59715, USA
| | - David K Weaver
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, USA
| | - Erika A Nunlist
- Department of Animal and Range Sciences, Montana State University, Bozeman, MT 59717, USA
| | - Bok F Sowell
- Department of Animal and Range Sciences, Montana State University, Bozeman, MT 59717, USA
| | - Erik Peterson
- School of the Environment, Washington State University, Pullman, WA 99163, USA
| | - Robert K D Peterson
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, USA
| |
Collapse
|
2
|
Hatch KA, Kester KA, Loveless A, Roeder BL, van Manen FT. Tooth wear and the apparent consumption of human foods among American black bears (Ursus americanus) in Great Smoky Mountains National Park, USA. Mamm Biol 2022. [DOI: 10.1007/s42991-022-00310-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
|
3
|
Bowersock NR, Okada H, Litt AR, Gunther KA, van Manen FT. Rub tree use and selection by American black bears and grizzly bears in northern Yellowstone National Park. URSUS 2022. [DOI: 10.2192/ursus-d-21-00009.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Nathaniel R. Bowersock
- Department of Ecology, Montana State University, P.O. Box 173460, Bozeman, MT 59717-3460, USA
| | - Hitomi Okada
- Department of Ecology, Montana State University, P.O. Box 173460, Bozeman, MT 59717-3460, USA
| | - Andrea R. Litt
- Department of Ecology, Montana State University, P.O. Box 173460, Bozeman, MT 59717-3460, USA
| | - Kerry A. Gunther
- Bear Management Office, Yellowstone Center for Resources, Yellowstone National Park, P.O. Box 168, Yellowstone National Park, WY 82190, 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
| |
Collapse
|
4
|
Hogan HRH, Hutzenbiler BDE, Robbins CT, Jansen HT. Changing lanes: seasonal differences in cellular metabolism of adipocytes in grizzly bears (Ursus arctos horribilis). J Comp Physiol B 2022; 192:397-410. [PMID: 35024905 DOI: 10.1007/s00360-021-01428-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 12/07/2021] [Accepted: 12/20/2021] [Indexed: 12/21/2022]
Abstract
Obesity is among the most prevalent of health conditions in humans leading to a multitude of metabolic pathologies such as type 2 diabetes and hyperglycemia. However, there are many wild animals that have large seasonal cycles of fat accumulation and loss that do not result in the health consequences observed in obese humans. One example is the grizzly bear (Ursus arctos horribilis) that can have body fat content > 40% that is then used as the energy source for hibernation. Previous in vitro studies found that hibernation season adipocytes exhibit insulin resistance and increased lipolysis. Yet, other aspects of cellular metabolism were not addressed, leaving this in vitro model incomplete. Thus, the current studies were performed to determine if the cellular energetic phenotype-measured via metabolic flux-of hibernating bears was retained in cultured adipocytes and to what extent that was due to serum or intrinsic cellular factors. Extracellular acidification rate and oxygen consumption rate were used to calculate proton efflux rate and total ATP defined as both ATP from glycolysis and from mitochondrial respiration. Hibernation adipocytes treated with hibernation serum produced less ATP and exhibited lower maximal respiration and glycolysis rates than active season adipocytes. These effects were reversed with serum from the opposite season. Insulin had little influence on total ATP production and lipolysis in both hibernation and active serum-treated adipocytes. Together, these results suggest that the metabolic suppression occurring in hibernation adipocytes are downstream of insulin signaling and likely due to a combined reduction in mitochondria number and/or function and glycolytic processes. Future elucidation of the serum components and the cellular mechanisms that enable alterations in mitochondrial function could provide a novel avenue for the development of treatments for human metabolic diseases.
Collapse
Affiliation(s)
- Hannah R Hapner Hogan
- School of Biological Sciences, College of Arts and Sciences, Washington State University, Pullman, WA, 99164, USA.
| | - Brandon D E Hutzenbiler
- Department Integrative Physiology and Neuroscience, College of Veterinary Medicine, Washington State University, Pullman, WA, 99164, USA.,School of the Environment, College of Agricultural, Human and Natural Resource Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Charles T Robbins
- School of Biological Sciences, College of Arts and Sciences, Washington State University, Pullman, WA, 99164, USA.,School of the Environment, College of Agricultural, Human and Natural Resource Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Heiko T Jansen
- Department Integrative Physiology and Neuroscience, College of Veterinary Medicine, Washington State University, Pullman, WA, 99164, USA.
| |
Collapse
|
5
|
Bowersock NR, Litt AR, Merkle JA, Gunther KA, van Manen FT. Responses of American black bears to spring resources. Ecosphere 2021. [DOI: 10.1002/ecs2.3773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Nathaniel R. Bowersock
- Department of Ecology Montana State University P.O. Box 173460 Bozeman Montana 59717‐3460 USA
| | - Andrea R. Litt
- Department of Ecology Montana State University P.O. Box 173460 Bozeman Montana 59717‐3460 USA
| | - Jerod A. Merkle
- Department of Zoology and Physiology University of Wyoming Department 3166 1000 East University Avenue Laramie Wyoming 82071 USA
| | - Kerry A. Gunther
- Bear Management Office Yellowstone Center for Resources Yellowstone National Park P.O. Box 168 Yellowstone National Park Wyoming 82190 USA
| | - Frank T. van Manen
- Interagency Grizzly Bear Study Team U.S. Geological Survey Northern Rocky Mountain Science Center 2327 University Way, Suite 2 Bozeman Montana 59715 USA
| |
Collapse
|
6
|
Christianson D, Coleman TH, Doan Q, Haroldson MA. Physiological consequences of consuming low-energy foods: herbivory coincides with a stress response in Yellowstone bears. CONSERVATION PHYSIOLOGY 2021; 9:coab029. [PMID: 34345432 PMCID: PMC8325456 DOI: 10.1093/conphys/coab029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/25/2021] [Accepted: 04/08/2021] [Indexed: 06/13/2023]
Abstract
Meat, fruit, seeds and other high-energy bear foods are often highly localized and briefly available and understanding which factors influence bear consumption of these foods is a common focus of bear conservation and ecology. However, the most common bear foods, graminoids and forbs, are more widespread but of lower quality. We poorly understand how herbage consumption impacts bear physiology, such as endocrine system function that regulates homeostasis and stress responses. Here, we described bear diets with a novel approach, measuring the concentration of chlorophyll in bear scats (faecal chlorophyll) to index the proportion of the recent diet that was composed of leaves from graminoids and forbs. We measured faecal chlorophyll and faecal cortisol in 351 grizzly (Ursus arctos, n = 255) and black bear (Ursus americanus, n = 96) scats from Yellowstone National Park in 2008-2009. We compared models of faecal chlorophyll and faecal cortisol concentrations considering the effects of spatial, dietary, scat and bear-specific factors including species. Faecal chlorophyll levels were the strongest predictor of faecal cortisol in a manner that suggested an endocrine response to a low-energy diet. Both compounds were highest during the spring and early summer months, overlapping the breeding season when higher energy foods were less available. Effects of scat composition, scat weathering, bear age, bear sex, species and other factors that have previously been shown to influence faecal cortisol in bears were not important unless faecal chlorophyll was excluded from models. The top models of faecal chlorophyll suggested grazing was primarily influenced by spatial attributes, with greater grazing closer to recreational trails, implying that elevated cortisol with grazing could be a response to anthropogenic activity. Our results confirm that higher stress hormone concentrations correspond with lower quality diets in bears, particularly grazing, and that faecal chlorophyll shows promise as a metric for studying grazing behaviour and its consequences.
Collapse
Affiliation(s)
- David Christianson
- Department of Ecosystem Science and Management, University of Wyoming, Laramie, WY 82071, USA
| | - Tyler H Coleman
- Sequoia-Kings Canyon National Park, National Park Service, 47050 Generals Highway, Three Rivers, CA 93271, USA
| | - Quint Doan
- School of Forestry and Environmental Studies, Yale University, 370 Prospect Street, New Haven CT 06511, 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 59717, USA
| |
Collapse
|
7
|
Towards an ecosystem model of infectious disease. Nat Ecol Evol 2021; 5:907-918. [PMID: 34002048 DOI: 10.1038/s41559-021-01454-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 03/25/2021] [Indexed: 02/03/2023]
Abstract
Increasingly intimate associations between human society and the natural environment are driving the emergence of novel pathogens, with devastating consequences for humans and animals alike. Prior to emergence, these pathogens exist within complex ecological systems that are characterized by trophic interactions between parasites, their hosts and the environment. Predicting how disturbance to these ecological systems places people and animals at risk from emerging pathogens-and the best ways to manage this-remains a significant challenge. Predictive systems ecology models are powerful tools for the reconstruction of ecosystem function but have yet to be considered for modelling infectious disease. Part of this stems from a mistaken tendency to forget about the role that pathogens play in structuring the abundance and interactions of the free-living species favoured by systems ecologists. Here, we explore how developing and applying these more complete systems ecology models at a landscape scale would greatly enhance our understanding of the reciprocal interactions between parasites, pathogens and the environment, placing zoonoses in an ecological context, while identifying key variables and simplifying assumptions that underly pathogen host switching and animal-to-human spillover risk. As well as transforming our understanding of disease ecology, this would also allow us to better direct resources in preparation for future pandemics.
Collapse
|
8
|
Shirane Y, Jimbo M, Yamanaka M, Nakanishi M, Mori F, Ishinazaka T, Sashika M, Tsubota T, Shimozuru M. Dining from the coast to the summit: Salmon and pine nuts determine the summer body condition of female brown bears on the Shiretoko Peninsula. Ecol Evol 2021; 11:5204-5219. [PMID: 34026001 PMCID: PMC8131783 DOI: 10.1002/ece3.7410] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 02/06/2021] [Accepted: 02/18/2021] [Indexed: 11/10/2022] Open
Abstract
Body condition in mammals fluctuates depending on energy intake and expenditure. For brown bears (Ursus arctos), high-protein foods facilitate efficient mass gain, while lipids and carbohydrates play important roles in adjusting dietary protein content to optimal levels to maximize energy intake. On the Shiretoko Peninsula, Hokkaido, Japan, brown bears have seasonal access to high-lipid pine nuts and high-protein salmon. To assess seasonal and annual fluctuation in the body condition of adult female brown bears in relation to diet and reproductive status, we conducted a longitudinal study in a special wildlife protection area on the Shiretoko Peninsula during 2012-2018. First, analyses of 2,079 bear scats revealed that pine nuts accounted for 39.8% of energy intake in August and salmon accounted for 46.1% in September and that their consumption by bears varied annually. Second, we calculated the ratio of torso height to torso length as an index of body condition from 1,226 photographs of 12 adult females. Results indicated that body condition continued to decline until late August and started to increase in September when salmon consumption increased. In addition, body condition began to recover earlier in years when consumption of both pine nuts and salmon was high. Furthermore, females with offspring had poorer body condition than solitary females, in particular in late August in years with low salmon consumption. Our findings suggest that coastal and subalpine foods, which are unique to the Shiretoko Peninsula, determine the summer body condition of female brown bears, as well as their survival and reproductive success.
Collapse
Affiliation(s)
- Yuri Shirane
- Graduate School of Veterinary MedicineHokkaido UniversitySapporoJapan
| | - Mina Jimbo
- Graduate School of Veterinary MedicineHokkaido UniversitySapporoJapan
| | | | | | - Fumihiko Mori
- Graduate School of Veterinary MedicineHokkaido UniversitySapporoJapan
| | | | - Mariko Sashika
- Graduate School of Veterinary MedicineHokkaido UniversitySapporoJapan
| | - Toshio Tsubota
- Graduate School of Veterinary MedicineHokkaido UniversitySapporoJapan
| | - Michito Shimozuru
- Graduate School of Veterinary MedicineHokkaido UniversitySapporoJapan
| |
Collapse
|
9
|
Rogers SA, Robbins CT, Mathewson PD, Carnahan AM, Manen FT, Haroldson MA, Porter WP, Rogers TR, Soule T, Long RA. Thermal constraints on energy balance, behaviour and spatial distribution of grizzly bears. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13727] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Savannah A. Rogers
- Bioinformatics and Computational Biology Program University of Idaho Moscow ID USA
| | - Charles T. Robbins
- School of the Environment and School of Biological Sciences Washington State University Pullman WA USA
| | - Paul D. Mathewson
- Department of Integrative Biology University of Wisconsin Madison Madison WI USA
| | | | - Frank T. Manen
- United States Geological SurveyInteragency Grizzly Bear Study Team Bozeman MT USA
| | - Mark A. Haroldson
- United States Geological SurveyInteragency Grizzly Bear Study Team Bozeman MT USA
| | - Warren P. Porter
- Department of Integrative Biology University of Wisconsin Madison Madison WI USA
| | - Taylor R. Rogers
- Department of Computer Science University of Idaho Moscow ID USA
| | - Terence Soule
- Department of Computer Science University of Idaho Moscow ID USA
| | - Ryan A. Long
- Bioinformatics and Computational Biology Program University of Idaho Moscow ID USA
- Department of Fish and Wildlife Sciences University of Idaho Moscow ID USA
| |
Collapse
|
10
|
Cameron MD, Hilderbrand GV, Joly K, Schmidt JH, Gustine DD, Mangipane LS, Mangipane B, Sorum MS. Body size plasticity in North American black and brown bears. Ecosphere 2020. [DOI: 10.1002/ecs2.3235] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Matthew D. Cameron
- National Park Service Gates of the Arctic National Park and Preserve 4175 Geist Road Fairbanks Alaska99709USA
| | - Grant V. Hilderbrand
- National Park Service Alaska Regional Office 240 W. 5th Avenue Anchorage Alaska99501USA
| | - Kyle Joly
- National Park Service Gates of the Arctic National Park and Preserve 4175 Geist Road Fairbanks Alaska99709USA
| | - Joshua H. Schmidt
- National Park Service Central Alaska Network 4175 Geist Road Fairbanks Alaska99709USA
| | - David D. Gustine
- National Park Service Grand Teton National Park PO Box 170 Moose Wyoming83012USA
| | - Lindsey S. Mangipane
- U. S. Fish and Wildlife Service Marine Mammals Management 1011 E. Tudor Road Anchorage Alaska99503USA
| | - Buck Mangipane
- National Park Service Lake Clark National Park and Preserve Port Alsworth Alaska99653USA
| | - Mathew S. Sorum
- National Park Service Gates of the Arctic National Park and Preserve 4175 Geist Road Fairbanks Alaska99709USA
| |
Collapse
|
11
|
Johnson HE, Lewis DL, Breck SW. Individual and population fitness consequences associated with large carnivore use of residential development. Ecosphere 2020. [DOI: 10.1002/ecs2.3098] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Heather E. Johnson
- Alaska Science Center U.S. Geological Survey 4210 University Drive Anchorage Alaska 99508 USA
| | - David L. Lewis
- Colorado Parks and Wildlife 415 Turner Drive Durango Colorado 81303 USA
| | - Stewart W. Breck
- USDA National Wildlife Research Center 4101 La Porte Ave Fort Collins Colorado 80521 USA
| |
Collapse
|
12
|
van Manen FT, Ebinger MR, Gustine DD, Haroldson MA, Wilmot KR, Whitman CL. Primarily resident grizzly bears respond to late-season elk harvest. URSUS 2019. [DOI: 10.2192/ursus-d-18-00018r2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- 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
| | - Michael R. Ebinger
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Interagency Grizzly Bear Study Team, 2327 University Way, suite #2, Bozeman, MT 59715, USA
| | - David D. Gustine
- National Park Service, Grand Teton National Park, P.O. Drawer 170, Moose, WY 83012, 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
| | - Katharine R. Wilmot
- National Park Service, Grand Teton National Park, P.O. Drawer 170, Moose, WY 83012, USA
| | - Craig L. Whitman
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Interagency Grizzly Bear Study Team, 2327 University Way, suite #2, Bozeman, MT 59715, USA
| |
Collapse
|
13
|
Furusaka S, Tochigi K, Yamazaki K, Naganuma T, Inagaki A, Koike S. Estimating the seasonal energy balance in Asian black bears and associated factors. Ecosphere 2019. [DOI: 10.1002/ecs2.2891] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- Shino Furusaka
- Tokyo University of Agriculture and Technology 3‐5‐8 Saiwai‐Cho Fuchu Tokyo 183‐8509 Japan
| | - Kahoko Tochigi
- Tokyo University of Agriculture and Technology 3‐5‐8 Saiwai‐Cho Fuchu Tokyo 183‐8509 Japan
| | - Koji Yamazaki
- Tokyo University of Agriculture 1‐1‐1 Sakuragaoka Setagaya Tokyo 156‐8502 Japan
| | - Tomoko Naganuma
- Tokyo University of Agriculture and Technology 3‐5‐8 Saiwai‐Cho Fuchu Tokyo 183‐8509 Japan
| | - Akino Inagaki
- Tokyo University of Agriculture and Technology 3‐5‐8 Saiwai‐Cho Fuchu Tokyo 183‐8509 Japan
| | - Shinsuke Koike
- Tokyo University of Agriculture and Technology 3‐5‐8 Saiwai‐Cho Fuchu Tokyo 183‐8509 Japan
| |
Collapse
|
14
|
Ueda M, Bell LS. Assessing dual hair sampling for isotopic studies of grizzly bears. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2019; 33:1475-1480. [PMID: 31148277 DOI: 10.1002/rcm.8495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 05/23/2019] [Accepted: 05/24/2019] [Indexed: 06/09/2023]
Abstract
RATIONALE The stable isotope ratios of carbon (δ13 C values), nitrogen (δ15 N values) and sulfur (δ34 S values) in bear hair can be used to obtain information on dietary history. Sample protocols often require hair sampling from multiple anatomical locations; however, there remains a question as to whether this is necessary for isotopic studies of hair. The purpose of this study was to determine whether significant differences can be observed for the δ13 C, δ15 N and δ34 S values between paired hair samples taken from the rump and shoulder of grizzly bears (Ursus arctos). METHODS Paired hair samples were collected from the rump and the shoulder of 81 grizzly bears in the Yukon, Canada. Hair samples were analyzed using a thermal combustion elemental analyzer coupled with a continuous flow isotope ratio mass spectrometer. RESULTS Statistical comparisons of paired hair samples for both males and females showed no meaningful differences in δ13 C, δ15 N and δ34 S values in hair taken from the rump and shoulder, and any observed differences fell within the instrumental error. CONCLUSIONS Based on these results, hair may be safely sampled on either the rump or the shoulder without loss of isotopic information and thus this finding allows for refinement of sampling.
Collapse
Affiliation(s)
- Momoko Ueda
- Centre for Forensic Research, School of Criminology, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Lynne S Bell
- Centre for Forensic Research, School of Criminology, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| |
Collapse
|
15
|
The effect of sex, age, and location on carnivory in Utah black bears (Ursus americanus). Oecologia 2019; 189:931-937. [PMID: 30989360 DOI: 10.1007/s00442-019-04385-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 03/14/2019] [Indexed: 10/27/2022]
Abstract
Ungulates are important to the diet of bears because they are high in protein, and the level of dietary protein strongly influences bear size. The size a bear obtains as an adult influences important life history characteristics, such as age of reproduction and reproductive success; therefore, it is important to know what foods are available to bears and how they are utilizing them. We tested hypotheses concerning the effect of age, sex, and location on black bear carnivory. We collected hair and vestigial premolar teeth from 49 Utah black bears, Ursus americanus according to the Utah Division of Wildlife Resources hunt unit. Hunt units differed in habitat quality and local ungulate density. We analyzed a vestigial premolar for the age of the bears and used analysis of the δ13C and δ15N values of the hairs of each bear to infer the degree of carnivory. δ15N of black bear hairs was positively correlated with increased availability of ungulates. There was a positive relationship between the δ15N of bear hairs and age in hunt units with the highest ungulate densities only. The δ15N and δ13C of black bear hairs were positively correlated, suggesting that bears are more carnivorous at higher altitudes. This study demonstrates the value of stable isotope analysis in understanding the feeding ecology of bears over broad geographic ranges. It demonstrates that ungulate availability is important to the feeding ecology of black bears in the Intermountain West.
Collapse
|
16
|
Ladle A, Steenweg R, Shepherd B, Boyce MS. The role of human outdoor recreation in shaping patterns of grizzly bear-black bear co-occurrence. PLoS One 2018; 13:e0191730. [PMID: 29389939 PMCID: PMC5794087 DOI: 10.1371/journal.pone.0191730] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 01/10/2018] [Indexed: 11/19/2022] Open
Abstract
Species’ distributions are influenced by a combination of landscape variables and biotic interactions with other species, including people. Grizzly bears and black bears are sympatric, competing omnivores that also share habitats with human recreationists. By adapting models for multi-species occupancy analysis, we analyzed trail camera data from 192 trail camera locations in and around Jasper National Park, Canada to estimate grizzly bear and black bear occurrence and intensity of trail use. We documented (a) occurrence of grizzly bears and black bears relative to habitat variables (b) occurrence and intensity of use relative to competing bear species and motorised and non-motorised recreational activity, and (c) temporal overlap in activity patterns among the two bear species and recreationists. Grizzly bears were spatially separated from black bears, selecting higher elevations and locations farther from roads. Both species co-occurred with motorised and non-motorised recreation, however, grizzly bears reduced their intensity of use of sites with motorised recreation present. Black bears showed higher temporal activity overlap with recreational activity than grizzly bears, however differences in bear daily activity patterns between sites with and without motorised and non-motorised recreation were not significant. Reduced intensity of use by grizzly bears of sites where motorised recreation was present is a concern given off-road recreation is becoming increasingly popular in North America, and can negatively influence grizzly bear recovery by reducing foraging opportunities near or on trails. Camera traps and multi-species occurrence models offer non-invasive methods for identifying how habitat use by animals changes relative to sympatric species, including humans. These conclusions emphasise the need for integrated land-use planning, access management, and grizzly bear conservation efforts to consider the implications of continued access for motorised recreation in areas occupied by grizzly bears.
Collapse
Affiliation(s)
- Andrew Ladle
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
| | - Robin Steenweg
- Wildlife Biology Program, College of Forestry and Conservation, University of Montana, Missoula, Montana, United States of America
| | | | - Mark S. Boyce
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
17
|
Keay JA, Robbins CT, Farley SD. Characteristics of a naturally regulated grizzly bear population. J Wildl Manage 2018. [DOI: 10.1002/jwmg.21425] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jeffrey A. Keay
- U.S. Geological SurveyAlaska Science CenterP.O. Box 9Denali National ParkAK99755USA
| | - Charles T. Robbins
- School of the Environment and School of Biological SciencesWashington State UniversityPullmanWA99164‐4236USA
| | - Sean D. Farley
- Alaska Department of Fish and Game333 Raspberry RoadAnchorageAK99518USA
| |
Collapse
|
18
|
Selecting the best stable isotope mixing model to estimate grizzly bear diets in the Greater Yellowstone Ecosystem. PLoS One 2017; 12:e0174903. [PMID: 28493929 PMCID: PMC5426898 DOI: 10.1371/journal.pone.0174903] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 03/17/2017] [Indexed: 11/19/2022] Open
Abstract
Past research indicates that whitebark pine seeds are a critical food source for Threatened grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE). In recent decades, whitebark pine forests have declined markedly due to pine beetle infestation, invasive blister rust, and landscape-level fires. To date, no study has reliably estimated the contribution of whitebark pine seeds to the diets of grizzlies through time. We used stable isotope ratios (expressed as δ13C, δ15N, and δ34S values) measured in grizzly bear hair and their major food sources to estimate the diets of grizzlies sampled in Cooke City Basin, Montana. We found that stable isotope mixing models that included different combinations of stable isotope values for bears and their foods generated similar proportional dietary contributions. Estimates generated by our top model suggest that whitebark pine seeds (35±10%) and other plant foods (56±10%) were more important than meat (9±8%) to grizzly bears sampled in the study area. Stable isotope values measured in bear hair collected elsewhere in the GYE and North America support our conclusions about plant-based foraging. We recommend that researchers consider model selection when estimating the diets of animals using stable isotope mixing models. We also urge researchers to use the new statistical framework described here to estimate the dietary responses of grizzlies to declines in whitebark pine seeds and other important food sources through time in the GYE (e.g., cutthroat trout), as such information could be useful in predicting how the population will adapt to future environmental change.
Collapse
|
19
|
Life in the fat lane: seasonal regulation of insulin sensitivity, food intake, and adipose biology in brown bears. J Comp Physiol B 2016; 187:649-676. [PMID: 27987017 DOI: 10.1007/s00360-016-1050-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 11/06/2016] [Accepted: 11/23/2016] [Indexed: 12/14/2022]
Abstract
Grizzly bears (Ursus arctos horribilis) have evolved remarkable metabolic adaptations including enormous fat accumulation during the active season followed by fasting during hibernation. However, these fluctuations in body mass do not cause the same harmful effects associated with obesity in humans. To better understand these seasonal transitions, we performed insulin and glucose tolerance tests in captive grizzly bears, characterized the annual profiles of circulating adipokines, and tested the anorectic effects of centrally administered leptin at different times of the year. We also used bear gluteal adipocyte cultures to test insulin and beta-adrenergic sensitivity in vitro. Bears were insulin resistant during hibernation but were sensitive during the spring and fall active periods. Hibernating bears remained euglycemic, possibly due to hyperinsulinemia and hyperglucagonemia. Adipokine concentrations were relatively low throughout the active season but peaked in mid-October prior to hibernation when fat content was greatest. Serum glycerol was highest during hibernation, indicating ongoing lipolysis. Centrally administered leptin reduced food intake in October, but not in August, revealing seasonal variation in the brain's sensitivity to its anorectic effects. This was supported by strong phosphorylated signal transducer and activator of transcription 3 labeling within the hypothalamus of hibernating bears; labeling virtually disappeared in active bears. Adipocytes collected during hibernation were insulin resistant when cultured with hibernation serum but became sensitive when cultured with active season serum. Heat treatment of active serum blocked much of this action. Clarifying the cellular mechanisms responsible for the physiology of hibernating bears may inform new treatments for metabolic disorders.
Collapse
|
20
|
Jouta J, Dietz MW, Reneerkens J, Piersma T, Rakhimberdiev E, Hallgrímsson GT, Pen I. Ecological forensics: using single point stable isotope values to infer seasonal schedules of animals after two diet switches. Methods Ecol Evol 2016. [DOI: 10.1111/2041-210x.12695] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Jeltje Jouta
- Department of Coastal Systems and Utrecht University NIOZ Royal Netherlands Institute for Sea Research P.O. Box 59, 1790 AB Den Burg Texel The Netherlands
- Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen P.O. Box 11103 9700 CC Groningen The Netherlands
| | - Maurine W. Dietz
- Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen P.O. Box 11103 9700 CC Groningen The Netherlands
| | - Jeroen Reneerkens
- Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen P.O. Box 11103 9700 CC Groningen The Netherlands
| | - Theunis Piersma
- Department of Coastal Systems and Utrecht University NIOZ Royal Netherlands Institute for Sea Research P.O. Box 59, 1790 AB Den Burg Texel The Netherlands
- Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen P.O. Box 11103 9700 CC Groningen The Netherlands
| | - Eldar Rakhimberdiev
- Department of Coastal Systems and Utrecht University NIOZ Royal Netherlands Institute for Sea Research P.O. Box 59, 1790 AB Den Burg Texel The Netherlands
- Department of Vertebrate Zoology Lomonosov Moscow State University 119991 Moscow Russia
| | | | - Ido Pen
- Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen P.O. Box 11103 9700 CC Groningen The Netherlands
| |
Collapse
|
21
|
Sciullo L, Thiemann GW, Lunn NJ. Comparative assessment of metrics for monitoring the body condition of polar bears in western Hudson Bay. J Zool (1987) 2016. [DOI: 10.1111/jzo.12354] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- L. Sciullo
- Department of Biology; York University; Toronto Ontario M3J 1P3 Canada
| | - G. W. Thiemann
- Faculty of Environmental Studies; York University; Toronto Ontario M3J 1P3 Canada
| | - N. J. Lunn
- Wildlife Research Division; Science and Technology Branch; Environment and Climate Change Canada; University of Alberta; Edmonton Alberta T6G 2E9 Canada
| |
Collapse
|
22
|
Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears. PLoS One 2016; 11:e0153702. [PMID: 27192407 PMCID: PMC4871523 DOI: 10.1371/journal.pone.0153702] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 04/03/2016] [Indexed: 12/02/2022] Open
Abstract
When fed ad libitum, ursids can maximize mass gain by selecting mixed diets wherein protein provides 17 ± 4% of digestible energy, relative to carbohydrates or lipids. In the wild, this ability is likely constrained by seasonal food availability, limits of intake rate as body size increases, and competition. By visiting locations of 37 individuals during 274 bear-days, we documented foods consumed by grizzly (Ursus arctos) and black bears (Ursus americanus) in Grand Teton National Park during 2004–2006. Based on published nutritional data, we estimated foods and macronutrients as percentages of daily energy intake. Using principal components and cluster analyses, we identified 14 daily diet types. Only 4 diets, accounting for 21% of days, provided protein levels within the optimal range. Nine diets (75% of days) led to over-consumption of protein, and 1 diet (3% of days) led to under-consumption. Highest protein levels were associated with animal matter (i.e., insects, vertebrates), which accounted for 46–47% of daily energy for both species. As predicted: 1) daily diets dominated by high-energy vertebrates were positively associated with grizzly bears and mean percent protein intake was positively associated with body mass; 2) diets dominated by low-protein fruits were positively associated with smaller-bodied black bears; and 3) mean protein was highest during spring, when high-energy plant foods were scarce, however it was also higher than optimal during summer and fall. Contrary to our prediction: 4) allopatric black bears did not exhibit food selection for high-energy foods similar to grizzly bears. Although optimal gain of body mass was typically constrained, bears usually opted for the energetically superior trade-off of consuming high-energy, high-protein foods. Given protein digestion efficiency similar to obligate carnivores, this choice likely supported mass gain, consistent with studies showing monthly increases in percent body fat among bears in this region.
Collapse
|
23
|
Ebinger MR, Haroldson MA, van Manen FT, Costello CM, Bjornlie DD, Thompson DJ, Gunther KA, Fortin JK, Teisberg JE, Pils SR, White PJ, Cain SL, Cross PC. Detecting grizzly bear use of ungulate carcasses using global positioning system telemetry and activity data. Oecologia 2016; 181:695-708. [PMID: 26971522 DOI: 10.1007/s00442-016-3594-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 02/22/2016] [Indexed: 11/24/2022]
Abstract
Global positioning system (GPS) wildlife collars have revolutionized wildlife research. Studies of predation by free-ranging carnivores have particularly benefited from the application of location clustering algorithms to determine when and where predation events occur. These studies have changed our understanding of large carnivore behavior, but the gains have concentrated on obligate carnivores. Facultative carnivores, such as grizzly/brown bears (Ursus arctos), exhibit a variety of behaviors that can lead to the formation of GPS clusters. We combined clustering techniques with field site investigations of grizzly bear GPS locations (n = 732 site investigations; 2004-2011) to produce 174 GPS clusters where documented behavior was partitioned into five classes (large-biomass carcass, small-biomass carcass, old carcass, non-carcass activity, and resting). We used multinomial logistic regression to predict the probability of clusters belonging to each class. Two cross-validation methods-leaving out individual clusters, or leaving out individual bears-showed that correct prediction of bear visitation to large-biomass carcasses was 78-88 %, whereas the false-positive rate was 18-24 %. As a case study, we applied our predictive model to a GPS data set of 266 bear-years in the Greater Yellowstone Ecosystem (2002-2011) and examined trends in carcass visitation during fall hyperphagia (September-October). We identified 1997 spatial GPS clusters, of which 347 were predicted to be large-biomass carcasses. We used the clustered data to develop a carcass visitation index, which varied annually, but more than doubled during the study period. Our study demonstrates the effectiveness and utility of identifying GPS clusters associated with carcass visitation by a facultative carnivore.
Collapse
Affiliation(s)
- Michael R Ebinger
- College of Forestry and Conservation, University of Montana, University Hall, Room 309, Missoula, MT, 59812, USA. .,Interagency Grizzly Bear Study Team, Northern Rocky Mountain Science Center, US Geological Survey, 2327 University Way, Suite 2, Bozeman, MT, 59715, USA. .,Department of Ecology, Montana State University, P.O. Box 173460, Bozeman, MT, 59717, USA.
| | - Mark A Haroldson
- Interagency Grizzly Bear Study Team, Northern Rocky Mountain Science Center, US Geological Survey, 2327 University Way, Suite 2, Bozeman, MT, 59715, USA
| | - Frank T van Manen
- Interagency Grizzly Bear Study Team, Northern Rocky Mountain Science Center, US Geological Survey, 2327 University Way, Suite 2, Bozeman, MT, 59715, USA
| | - Cecily M Costello
- College of Forestry and Conservation, University of Montana, University Hall, Room 309, Missoula, MT, 59812, USA.,Montana Fish, Wildlife and Parks, 490 N. Meridian Road, Kalispell, MT, 59901, USA
| | - Daniel D Bjornlie
- Large Carnivore Section, Wyoming Game and Fish Department, 260 Buena Vista, Lander, WY, 82520, USA
| | - Daniel J Thompson
- Large Carnivore Section, Wyoming Game and Fish Department, 260 Buena Vista, Lander, WY, 82520, USA
| | - Kerry A Gunther
- Bear Management Office, Yellowstone Center for Resources, Yellowstone National Park, P.O. Box 168, Yellowstone National Park, WY, 82190, USA
| | - Jennifer K Fortin
- College of Forestry and Conservation, University of Montana, University Hall, Room 309, Missoula, MT, 59812, USA.,School of Biological Sciences, Washington State University, P.O. Box 644236, Pullman, WA, 99164-4236, USA
| | - Justin E Teisberg
- School of Biological Sciences, Washington State University, P.O. Box 644236, Pullman, WA, 99164-4236, USA.,Grizzly Bear Recovery Program, US Fish and Wildlife Service, 385 Fish Hatchery Road, Libby, MT, 59923, USA
| | - Shannon R Pils
- Interagency Grizzly Bear Study Team, Northern Rocky Mountain Science Center, US Geological Survey, 2327 University Way, Suite 2, Bozeman, MT, 59715, USA.,Shoshone National Forest, US Forest Service, Wapiti Ranger District, 203A Yellowstone Avenue, Cody, WY, 82414, USA
| | - P J White
- National Park Service, Yellowstone Center for Resources, Yellowstone National Park, P.O. Box 168, Yellowstone National Park, WY, 82190, USA
| | - Steven L Cain
- Grand Teton National Park, P.O. Box 170, Moose, WY, 83012, USA.,Grand Teton National Park Foundation, P.O. Box 249, Moose, WY, 83012, USA
| | - Paul C Cross
- Interagency Grizzly Bear Study Team, Northern Rocky Mountain Science Center, US Geological Survey, 2327 University Way, Suite 2, Bozeman, MT, 59715, USA
| |
Collapse
|
24
|
Sorensen A, Stenhouse G, Bourbonnais M, Nelson T. Effects of habitat quality and anthropogenic disturbance on grizzly bear (Ursus arctos horribilis) home-range fidelity. CAN J ZOOL 2015. [DOI: 10.1139/cjz-2015-0095] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the Rocky Mountain eastern slopes of Alberta, Canada, grizzly bears (Ursus arctos horribilis Ord, 1815) live in a landscape heavily impacted by industrial development and human disturbance. We characterized the role of changing habitat quality and new disturbance features on patterns of grizzly bear seasonal home-range fidelity and drift by comparing consecutive-year seasonal home ranges. We relied on the geographic technique “spatial–temporal analysis of moving polygons” (STAMP) to examine changes in habitat quality and new development between zones of home-range fidelity, expansion, and contraction. Areas considered to be high-quality habitat were selected at a greater frequency than available and retained in zones of home-range fidelity, but also vacated during home-range contraction. Areas of decreasing habitat quality were equally present in zones of contraction, expansion, and stability. The proportion of new forest harvest areas and roads developed within the past year did not differ between zones of home-range change, but the proportion of new well sites was higher in contraction zones than in stability zones. Our results showed that while considerable drift occurs, changes in habitat quality and recent anthropogenic disturbances cannot account for annual variation in home ranges, suggesting other important factors influencing behaviour and movement.
Collapse
Affiliation(s)
- A.A. Sorensen
- Foothills Research Institute, Grizzly Bear Program, 1176 Switzer Drive, Hinton, AB T7V 1V3, Canada
| | - G.B. Stenhouse
- Foothills Research Institute, Grizzly Bear Program, 1176 Switzer Drive, Hinton, AB T7V 1V3, Canada
| | - M.L. Bourbonnais
- Spatial Pattern Analysis and Research Laboratory, Department of Geography, University of Victoria, Victoria, BC V8W 3R4, Canada
| | - T.A. Nelson
- Spatial Pattern Analysis and Research Laboratory, Department of Geography, University of Victoria, Victoria, BC V8W 3R4, Canada
| |
Collapse
|
25
|
van Manen FT, Haroldson MA, Bjornlie DD, Ebinger MR, Thompson DJ, Costello CM, White GC. Density dependence, whitebark pine, and vital rates of grizzly bears. J Wildl Manage 2015. [DOI: 10.1002/jwmg.1005] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Frank T. van Manen
- U.S. Geological SurveyNorthern Rocky Mountain Science Center, Interagency Grizzly Bear Study Team2327 University Way, Suite 2BozemanMT59715USA
| | - Mark A. Haroldson
- U.S. Geological SurveyNorthern Rocky Mountain Science Center, Interagency Grizzly Bear Study Team2327 University Way, Suite 2BozemanMT59715USA
| | | | - Michael R. Ebinger
- College of Forestry and ConservationUniversity MontanaUniversity Hall, Room 309MissoulaMT59812USA
| | | | - Cecily M. Costello
- College of Forestry and ConservationUniversity MontanaUniversity Hall, Room 309MissoulaMT59812USA
| | - Gary C. White
- Department of Fish, Wildlife, and Conservation BiologyColorado State UniversityFort CollinsCO80523USA
| |
Collapse
|
26
|
López-Alfaro C, Coogan SCP, Robbins CT, Fortin JK, Nielsen SE. Assessing Nutritional Parameters of Brown Bear Diets among Ecosystems Gives Insight into Differences among Populations. PLoS One 2015; 10:e0128088. [PMID: 26083536 PMCID: PMC4470632 DOI: 10.1371/journal.pone.0128088] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 04/22/2015] [Indexed: 11/19/2022] Open
Abstract
Food habit studies are among the first steps used to understand wildlife-habitat relationships. However, these studies are in themselves insufficient to understand differences in population productivity and life histories, because they do not provide a direct measure of the energetic value or nutritional composition of the complete diet. Here, we developed a dynamic model integrating food habits and nutritional information to assess nutritional parameters of brown bear (Ursus arctos) diets among three interior ecosystems of North America. Specifically, we estimate the average amount of digestible energy and protein (per kilogram fresh diet) content in the diet and across the active season by bears living in western Alberta, the Flathead River (FR) drainage of southeast British Columbia, and the Greater Yellowstone Ecosystem (GYE). As well, we estimate the proportion of energy and protein in the diet contributed by different food items, thereby highlighting important food resources in each ecosystem. Bear diets in Alberta had the lowest levels of digestible protein and energy through all seasons, which might help explain the low reproductive rates of this population. The FR diet had protein levels similar to the recent male diet in the GYE during spring, but energy levels were lower during late summer and fall. Historic and recent diets in GYE had the most energy and protein, which is consistent with their larger body sizes and higher population productivity. However, a recent decrease in consumption of trout (Oncorhynchus clarki), whitebark pine nuts (Pinus albicaulis), and ungulates, particularly elk (Cervus elaphus), in GYE bears has decreased the energy and protein content of their diet. The patterns observed suggest that bear body size and population densities are influenced by seasonal availability of protein an energy, likely due in part to nutritional influences on mass gain and reproductive success.
Collapse
Affiliation(s)
- Claudia López-Alfaro
- Department of Renewable Resources, University of Alberta, 751 GSB, Edmonton, T6G 2H1, AB, Canada
- Departamento de Ciencias Ambientales y Recursos Naturales Renovables, Universidad de Chile, Av. Santa Rosa, 11315, Casilla 9206, Santiago Chile
- * E-mail:
| | - Sean C. P. Coogan
- Department of Renewable Resources, University of Alberta, 751 GSB, Edmonton, T6G 2H1, AB, Canada
- School of Biological Sciences and the Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia
| | - Charles T. Robbins
- School of the Environment and School of Biological Sciences, Washington State University, Pullman, WA, United States of America
| | - Jennifer K. Fortin
- School of Biological Sciences, Washington State University, Pullman, WA, United States of America
| | - Scott E. Nielsen
- Department of Renewable Resources, University of Alberta, 751 GSB, Edmonton, T6G 2H1, AB, Canada
| |
Collapse
|
27
|
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.
Collapse
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
| |
Collapse
|
28
|
Schwartz CC, Teisberg JE, Fortin JK, Haroldson MA, Servheen C, Robbins CT, van Manen FT. Use of isotopic sulfur to determine whitebark pine consumption by Yellowstone bears: A reassessment. WILDLIFE SOC B 2014. [DOI: 10.1002/wsb.426] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Charles C. Schwartz
- United States Geological Survey; Northern Rocky Mountain Science Center; Interagency Grizzly Bear Study Team; 2327 University Way Suite 2 Bozeman MT 59715 USA
| | - Justin E. Teisberg
- School of Biological Sciences; Washington State University; P.O. Box 644236 Pullman WA 99164 USA
| | - Jennifer K. Fortin
- School of Biological Sciences; Washington State University; P.O. Box 644236 Pullman WA 99164 USA
| | - Mark A. Haroldson
- United States Geological Survey; Northern Rocky Mountain Science Center; Interagency Grizzly Bear Study Team; 2327 University Way Suite 2 Bozeman MT 59715 USA
| | - Christopher Servheen
- United States Fish and Wildlife Service; University of Montana; Missoula MT 59812 USA
| | - Charles T. Robbins
- Schools of the Environment and Biological Sciences; Washington State University; P.O. Box 644236 Pullman WA 99164 USA
| | - Frank T. van Manen
- United States Geological Survey; Northern Rocky Mountain Science Center; Interagency Grizzly Bear Study Team; 2327 University Way Suite 2 Bozeman MT 59715 USA
| |
Collapse
|
29
|
Bjornlie DD, Van Manen FT, Ebinger MR, Haroldson MA, Thompson DJ, Costello CM. Whitebark pine, population density, and home-range size of grizzly bears in the greater yellowstone ecosystem. PLoS One 2014; 9:e88160. [PMID: 24520354 PMCID: PMC3919729 DOI: 10.1371/journal.pone.0088160] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 01/04/2014] [Indexed: 11/18/2022] Open
Abstract
Changes in life history traits of species can be an important indicator of potential factors influencing populations. For grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE), recent decline of whitebark pine (WBP; Pinus albicaulis), an important fall food resource, has been paired with a slowing of population growth following two decades of robust population increase. These observations have raised questions whether resource decline or density-dependent processes may be associated with changes in population growth. Distinguishing these effects based on changes in demographic rates can be difficult. However, unlike the parallel demographic responses expected from both decreasing food availability and increasing population density, we hypothesized opposing behavioral responses of grizzly bears with regard to changes in home-range size. We used the dynamic changes in food resources and population density of grizzly bears as a natural experiment to examine hypotheses regarding these potentially competing influences on grizzly bear home-range size. We found that home-range size did not increase during the period of whitebark pine decline and was not related to proportion of whitebark pine in home ranges. However, female home-range size was negatively associated with an index of population density. Our data indicate that home-range size of grizzly bears in the GYE is not associated with availability of WBP, and, for female grizzly bears, increasing population density may constrain home-range size.
Collapse
Affiliation(s)
- Daniel D. Bjornlie
- Large Carnivore Section, Wyoming Game and Fish Department, Lander, Wyoming, United States of America
- * E-mail:
| | - Frank T. Van Manen
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Interagency Grizzly Bear Study Team, Bozeman, Montana, United States of America
| | - Michael R. Ebinger
- University of Montana, College of Forestry and Conservation, Missoula, Montana, United States of America
| | - Mark A. Haroldson
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Interagency Grizzly Bear Study Team, Bozeman, Montana, United States of America
| | - Daniel J. Thompson
- Large Carnivore Section, Wyoming Game and Fish Department, Lander, Wyoming, United States of America
| | - Cecily M. Costello
- University of Montana, College of Forestry and Conservation, Missoula, Montana, United States of America
| |
Collapse
|