Food Habits of Black Bear in the San Gabriel Mountains of Southern California

Stubblefield, Cynthia H.

doi:10.2307/3671439

Cited by 8 publications

(5 citation statements)

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“…Zeigenfuss, United State Geological Survey, 2001 unpublished report), and bears in the contemporary population no longer avoid human-use areas (Baldwin 2008). Although current use of anthropogenic foods (5.2% of fecal volume annually) are not as high as some other populations (Yosemite National Park, California: 15% by volume (Graber and White 1983); San Gabriel Mountains, California: 33% by volume (Stubblefield 1993)), the trend of increased use parallels that observed in the Lake Tahoe region of Nevada Berger 2003a, 2003b), which ultimately led to emigration of most bears out of wildland areas.…”

Section: Notementioning

confidence: 91%

Foods and nutritional components of diets of black bear in Rocky Mountain National Park, Colorado

Baldwin

Bender

2009

Can. J. Zool.

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We used scat analysis to determine diets and relative nutritional values of diets for black bears (Ursus americanus Pallas, 1780) in Rocky Mountain National Park, Colorado, from 2003 to 2006, and compared foods consumed and nutritional components to identify important sources of fecal gross energy (GE), crude fat (CF), and fecal nitrogen (FN) in annual and seasonal diets. Patterns of use of food classes followed typical seasonal patterns for bears, although use of animal matter was among the highest reported (>49% annually). Use of animal matter increased after spring, although crude protein levels in bear diets were always >25%. GE was typically lowest for grasses and other herbaceous plants and highest for ants and ungulates; FN was strongly positively related to most animal sources, but negatively correlated with vegetative matter; and CF showed the strongest positive relationship with ungulates and berries, with the latter likely influenced by the presence of seeds. Compared with historic data (1984)(1985)(1986)(1987)(1988)(1989)(1990)(1991), contemporary diets included substantially greater prevalence of anthropogenic foods, which likely contributed to increases in size, condition, and productivity of the contemporary bear population. Management strategies are needed to increase quantity and quality of natural foods while minimizing dependence on anthropogenic sources. Résumé: Une analyse des fèces nous a servi à déterminer le régime alimentaire et la valeur nutritionnelle relative de ce régime chez des ours noirs (Ursus americanus Pallas, 1780) dans le parc national des Montagnes Rocheuses, Colorado, de 2003 à 2006; nous avons comparé les aliments consommés et les composantes nutritives afin d'identifier les sources importantes d'énergie fécale brute (GE), de lipides bruts (CF) et d'azote fécal (FN) dans les régimes alimentaires annuels et saisonniers. Les patrons d'utilisation des diverses classes d'aliments suivent les patrons saisonniers typiques des ours, bien que le taux d'utilisation de matière animale soit parmi les plus élevés (>49 % sur une base annuelle) jamais observés. L'utilisation de matière animale augmente après le printemps bien que les concentrations brutes de protéines soient toujours >25 %. Les valeurs de GE sont typiquement minimales pour les herbes et les autres plantes herbacées et maximales pour les fourmis et les ongulés; il y a une forte corrélation positive entre FN et la plupart des sources alimentaires animales et une corrélation négative avec la matière végétale; la plus forte relation positive existe entre CF et les ongulés et les baies, dans ce dernier cas vraisemblablement influencée par la présence de graines. Par comparaison aux données du passé (1984)(1985)(1986)(1987)(1988)(1989)(1990)(1991), les régimes alimentaires actuels comprennent une fréquence nettement plus élevée d'aliments d'origine humaine, ce qui contribue vraisemblablement à l'augmentation de la taille, de la condition et de la productivité de la population présente d'ours. Il faudrait établir des stratégies...

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Section: Notementioning

confidence: 91%

Foods and nutritional components of diets of black bear in Rocky Mountain National Park, Colorado

Baldwin

Bender

2009

Can. J. Zool.

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“…Moss (1972) and Stubblefield (1992) studied black bear ecology in the San Gabriel Mountains. Novick investigated habitat preferences and denning characteristics of black bears in the San Bernardino Mountains (Novick 1979; hunter take figures from southern California suggest they are either stable or increasing in most of the assessment area ( fig.…”

Section: Black Bear (Ursus Americanus)mentioning

confidence: 99%

Southern California Mountains and Foothills Assessment: Habitat and Species Conservation Issues

Stephenson¹,

Calcarone²

2016

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Stephenson, John R.; Calcarone, Gena M. 1999. Southern California mountains and foothills assessment: habitat and species conservation issues. General Technical Report GTR-PSW-175. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; 402 p. The Southern California Mountains and Foothills Assessment: Habitat and SpeciesConservation Issues provides detailed information about current conditions and trends for ecological systems and species in the region. This information can be used by land managers to develop broad land management goals and priorities and provides the context for decisions specific to smaller geographic areas. The assessment area covers 6.1 million acres, of which 56 percent are national forest system lands. Over eighteen million people live in the coastal basin bordering the assessment area. As compared to historic conditions, mountain and foothill ecosystems in this region have undergone dramatic changes. Forested landscapes are more susceptible to stand-replacing fires. Invasive non-native species have become widely established, causing a decline in habitat capability for many native plants and animals. An extensive network of dams and diversions has altered aquatic systems. Some areas of high ecological integrity remain and can serve as building blocks for restoration. Biological diversity is not uniformly distributed across the landscape; rare species in particular tend to be concentrated in certain habitats. Key areas of high ecological integrity and rare species assemblages are identified in this report. This assessment provides a rich information base, including over eighty mapped themes with associated models and databases, from which future decisions can benefit.Retrieval Terms: Southern California, ecosystem, biodiversity, land management Publisher:Albany, California The U.S. Department of Agriculture (USDA) prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political beliefs, and marital or familial status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (braille, large print, audiotape, etc.) should contact USDA's TARGET Center at 202-720-2600 (voice and TDD).To file a compliant, write the Secretary of Agriculture, U.S. Department of Agriculture, Washington, DC 20250, or call (800) 245-6340 (voice) or (202) 720-1127 (TDD). USDA is an equal employment opportunity employer. iii Contents ............................................................................................................... iii List of Figures and Tables ........................................................................................ vii Preface ............................................................................................................... xiii Contributors.......................................................................................................... xiv C...

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“…Given our observation of bears at the study site, there is a risk of predation on desert tortoises by this potentially novel predator. The probability of bear predation is very likely low due to minimal range and habitat overlap between the species and the fact that California black bears have a diet dominated by plant material (Boyer 1976;Stubblefield 1993). However, the fact that turtles are included in the diets of bears worldwide supports the possibility that it can occur.…”

Section: Bear Speciesmentioning

confidence: 99%

“…Date and time stamps of the wildlife trail camera are shown at the top of the image along with air temperature. in the spring, fruit and acorns in the summer, and fruit, acorns and other nuts in the fall (Boyer 1976;Stubblefield 1993). Although we did not observe a predatory event per se, the omnivorous diet of bears (including black bears) does include turtles (Table 1), so the potential exists for predatory encounters when the species meet.…”

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confidence: 99%

Black Bears (Ursus americanus) as a Novel Potential Predator of Agassiz's Desert Tortoises (Gopherus agassizii) at a California Wind Energy Facility

Lovich

Delaney

Briggs

et al. 2014

Bulletin, Southern California Academy of Sciences

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Areas of significant topographic relief often form ecoclines, resulting in stratified life zones each with distinct communities of plants and animals (Attrill and Rundle 2002). Contact zones, or ecological boundaries along ecoclines, allow unique plant and animal assemblages that are not normally considered to be syntopic, to mix in varying degrees. The boundaries of ecoclines are thus both spatial and ecological and when these boundaries are crossed unique interactions can occur, including unexpected predator and prey interactions.The eastern San Bernardino Mountains in southern California range from about 300-3,506 m and support a wide range of as many as 1 1 distinct life zones along an ecocline extending from Sonoran Desert on the east side and Mojave Desert on the north side, to an alpine ecosystem near the summit (Schoenherr 1992). In this paper we report an interaction between black bears ( Ursus americanus) and Agassiz's desert tortoises ( Gopherus agassizii ). These two species have not previously been reported to interact due to their substantially different habitat preferences. In addition, given the paucity of bear and turtle interactions in general, we provide a review of the scientific literature on the topic, since bears are known to eat turtles on an opportunistic basis.The study site is located in the foothills of the southeastern San Bernardino Mountains in Riverside County, California, near the city of Palm Springs (33°57'06"N, 116°40'02"W, WGS84). Known locally as "Mesa," the site is located on land administered by the Bureau of Land Management for wind energy generation since 1983. Extensive studies of G. agasszii have been conducted at the site since 1 994, including investigations on growth, demography and survivorship (Lovich et al. 2011b), fire ecology (Lovich et al. 2011c), habitat selection (Lovich and Daniels 2000), the effects of climate on behavior and reproductive ecology (Ennen et al. 2012b;Lovich et al. 2012;Lovich et al. 1999), nesting ecology (Ennen et al. 2012a) and the impacts of wind energy operation and maintenance on tortoises (Lovich and Ennen 2013;Lovich et al. 2011a).Mesa is at the extreme western edge of the Lower Colorado River Subdivision of the Sonoran Desert ecosystem, commonly referred to as the "Colorado Desert" (Turner and Brown 1994). Because of its location near several major ecosystems, vegetation at the site

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Food Habits of Black Bear in the San Gabriel Mountains of Southern California

Cited by 8 publications

References 0 publications

Foods and nutritional components of diets of black bear in Rocky Mountain National Park, Colorado

Foods and nutritional components of diets of black bear in Rocky Mountain National Park, Colorado

Southern California Mountains and Foothills Assessment: Habitat and Species Conservation Issues

Black Bears (Ursus americanus) as a Novel Potential Predator of Agassiz's Desert Tortoises (Gopherus agassizii) at a California Wind Energy Facility

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