Effect of Hard Mast Production on Foraging and Sex-Specific Behavior of the Asiatic Black Bear (<i>Ursus thibetanus</i>)

Koike, Shinsuke; Kozakai, Chinatsu; Nemoto, Yasuyuki; Masaki, Takashi; Yamazaki, Koji; S, Abe; Nakajima, Ami; Umemura, Yoshihiro; Kaji, Koichi

doi:10.3106/041.037.0103

Cited by 62 publications

(31 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Female bears move great distances (Koike et al . ) and have high activity levels (Garshelis & Pelton ), especially during low mast years (Mazur, Klimley & Folger ). High levels of activity by lactating black bears suggest that increased foraging efforts are required to meet the additional energy and protein requirements for lactation and cub growth (Eagle & Pelton ).…”

Section: Discussionmentioning

confidence: 99%

Measuring the realized niches of animals using stable isotopes: from rats to bears

Hopkins

Kurle

2015

Methods Ecol Evol

View full text Add to dashboard Cite

Summary1. Stable isotope analysis is a powerful method for estimating the impacts animals have on their environment (resource use), revealing their ecological niches. 2. We demonstrated the use of a stable isotope mixing model for measuring the ecological niches of consumers. In particular, we used the model IsotopeR to estimate the resource use of two species with complex, omnivorous diets: invasive Norway rats from the Aleutian Islands, AK, and American black bears from Yosemite National Park, CA. Marginal posterior distributions for major food sources (for populations, groups and individuals) described the resource axes that partly define the realized niches of these omnivores. We used measures of these resource axes to inform resource management in the Aleutians and Yosemite. 3. Results from our analyses confirm that coastal rats did not rely on marine birds on rat-infested islands in the Aleutians. Instead, rats foraged primarily on terrestrial plants and preferred amphipods when they were available. We also use stable isotopes to confirm that plants and acorns are the largest contributors to black bear nutrition in Yosemite and learned that female bears foraged for acorns and pine nuts more heavily than males. 4. Although it is unclear if Norway rats can maintain viable populations in the Aleutians without access to marine-derived animal protein, results from our analyses suggest their dependence on such nutrients. In addition, sex-specific differences in foraging for high-fat acorns and pine nuts in Yosemite suggest black bear populations in the Sierra Nevada may be limited by the productivity and health of hard mast species. As demonstrated here, stable isotope analysis has wide applicability for investigating the resource use and ecological niches of animals. We anticipate and encourage its rapid development in this fundamental field of ecology.

show abstract

Section: Discussionmentioning

confidence: 99%

Measuring the realized niches of animals using stable isotopes: from rats to bears

Hopkins

Kurle

2015

Methods Ecol Evol

View full text Add to dashboard Cite

show abstract

“…Indeed, omnivores have opportunistic, variable seasonal diets (Koike et al 2008, Koike et al 2012) and can travel long distances across diverse habitats (Clevenger et al 1990, Huber and Roth 1993, Quenette et al 2001, Dahle and Swenson 2003.…”

Section: Introductionmentioning

confidence: 99%

Exploring the potential of brown bear (Ursus arctos arctos) as a long-distance seed disperser: a pilot study in South-Western Europe

et al. 2017

View full text Add to dashboard Cite

Plant dispersal is crucial to maintaining plant community dynamics, especially in the current context of rapid environmental changes such as global warming and landscape fragmentation. We seized the opportunity to carry out a pilot study on endozoochorous dispersal by the endangered Pyrenean brown bear. We based our study on faeces collected by the Brown Bear Network and location data from three bears fitted with GPS collars and translocated from Slovenia to the Pyrenees in 2006. We studied 39 faecal samples, 25 of which contained seeds from two to three different taxa. We identified a total of 47 plant taxa, 30 to the genus level and 21 to the species level. The seeds from plants bearing fleshy fruits: Vaccinium myrtillus or uliginosum, Rubus idaeus, Malus sylvestris and Sorbus sp., but also dry fruits: Thymus sp., Betula pendula or alba, were the most frequently recovered. We estimated average distances moved by bears to vary from 0.85 to 1.34 km over a 6-h period, corresponding to the median gut retention time, GRT 50% for their berry-based diet in summer and fall. Bears may thus promote the long-distance dispersal of fleshy forest fruits, over longer distances than other sympatric mammals, involved in the dispersal of plants from open areas.

show abstract

“…Males may have advantages over females in finding new productive patches because males tend to have larger home ranges (Yamazaki ), and in our study area, males moved over longer distances in poor mast years (Koike et al. ). Second, male bears tend to disperse from the natal area, whereas females usually stay near the maternal home range (Kozakai et al.…”

Section: Discussionmentioning

confidence: 87%

“…, Koike et al. ). Therefore, the energy balance likely varies widely between good and poor mast years and between males and females.…”

Section: Introductionmentioning

confidence: 99%

Estimating the seasonal energy balance in Asian black bears and associated factors

et al. 2019

Self Cite

View full text Add to dashboard Cite

Energy balance (i.e., energy intake minus energy expenditure) is an essential factor when evaluating an animal's nutritional state. We aimed to identify periods of the year that are most important for Asian black bears (Ursus thibetanus) in terms of energy balance. We estimated bears’ daily energy balance by estimating energy intake based on the energy content (kcal/g) of major food items, their average ingestion rate (g/min), and daily feeding time (min) and by estimating energy expenditure using an equation for the costs of resting, traveling, and feeding based on behavioral data of 34 bears fitted with GPS collars in central Japan. Because food habits of bears change seasonally, we estimated daily energy balance for each month. And, because bears change their feeding behavior depending on the availability of hard mast, we made separate estimations for years of good and poor mast conditions during autumn. We identified major food items from fecal analysis and calculated the gross energy content per unit for each item. Based on direct observation of bears feeding over 10 yr, we measured ingestion rates of the major food items; Quercus crispula acorns on the tree had the highest ingestion rate, whereas the values of other items did not show notable characteristics. The variability of energy expenditure rose moderately in good mast years, except for males. On the other hand, there was a bimodal pattern of energy intake and energy balance, declining from May to July, rising again from August to October, and declining in November. The peak of energy intake and energy balance was larger in good mast years than in poor mast years only for females, whereas the cumulative energy balance in good mast years was larger than in poor mast years for both sexes. After poor mast years, the cumulative energy balance of males becomes negative in February, during hibernation, and did not exceed zero until August, even if they could start feeding in May. Thus, further longitudinal studies that examine cumulative energy balance, rather than energy balance alone, are necessary to clarify the seasonal change in the nutritional state of Asian black bears.

show abstract

Effect of Hard Mast Production on Foraging and Sex-Specific Behavior of the Asiatic Black Bear (Ursus thibetanus)

Cited by 62 publications

References 19 publications

Measuring the realized niches of animals using stable isotopes: from rats to bears

Measuring the realized niches of animals using stable isotopes: from rats to bears

Exploring the potential of brown bear (Ursus arctos arctos) as a long-distance seed disperser: a pilot study in South-Western Europe

Estimating the seasonal energy balance in Asian black bears and associated factors

Contact Info

Product

Resources

About