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Mori T, Mori SN, Izumiyama S. Temporal and individual variation in the feeding habits of Asiatic black bears ( Ursus thibetanus). Ecol Evol 2024; 14:e11562. [PMID: 38988342 PMCID: PMC11233272 DOI: 10.1002/ece3.11562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 05/29/2024] [Accepted: 05/30/2024] [Indexed: 07/12/2024] Open
Abstract
Foraging plays a vital role in the survival of wildlife, and shifts in food availability can impact species fitness and survival. Ursids are known to consume a wide variety of foods and are known to be opportunistic omnivores. Consequently, seasonal shifts in diet, which correspond to temporal and spatial shifts in the availability of food resources, have long captivated researchers studying the foraging behavior of Ursidae. Nevertheless, comprehensive dietary studies encompassing both the population and individual levels remain scarce. In this study, we investigated the dietary patterns of Asiatic black bears (Ursus thibetanus) at both the population and individual levels, using data collected through GPS collars and field surveys of individual bear scat samples in Nagano Prefecture, Japan, from 2016 to 2020. From early April to late June, bears mainly foraged on green vegetation. During this period, male and large-bodied female bears showed a strong preference for green vegetation. Small-bodied female bears also ate mostly green vegetation but tended to consume more fruit than other bears towards the end of this period. From June to October, bears' diets included a substantial amount of fruit, with notable peaks in fruit consumption in late June and early September. During the summer months, female bears often incorporated social insects into their diet compared to the population-level trend. In mid-September, the consumption of seeds from the Fagaceae family surged, becoming the primary dietary component during this period. This trend was consistently observed across the population. These findings underscore the importance conducting in-depth dietary analyses that take into account individual characteristics such as sex, age, and body weight.
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Affiliation(s)
- Tomoki Mori
- Institute for Mountain Science Shinshu University Minami-minowa, Kami-Ina Japan
- Present address: Research Center for Wildlife Management Gifu University Gifu Japan
| | - Saki N Mori
- Graduate School of Science and Technology Shinshu University Minami-minowa, Kami-Ina Japan
| | - Shigeyuki Izumiyama
- Institute for Mountain Science Shinshu University Minami-minowa, Kami-Ina Japan
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Lazarus M, Orct T, Sergiel A, Vranković L, Marijić VF, Rašić D, Reljić S, Aladrović J, Zwijacz-Kozica T, Zięba F, Jurasović J, Erk M, Maślak R, Selva N, Huber Đ. Metal(loid) exposure assessment and biomarker responses in captive and free-ranging European brown bear (Ursus arctos). ENVIRONMENTAL RESEARCH 2020; 183:109166. [PMID: 32004830 DOI: 10.1016/j.envres.2020.109166] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/29/2019] [Accepted: 01/22/2020] [Indexed: 06/10/2023]
Abstract
We investigated the level of five non-essential metal(loid)s (As, Cd, Hg, Tl, Pb) and nine essential metals (Mg, Ca, Mn, Fe, Co, Cu, Zn, Se, Mo) in hair and blood components of captive and free-ranging European brown bear populations in Croatia and Poland. Metal(loid) associations with biomarkers of oxidative stress (superoxide dismutase, SOD; glutathione-peroxidase, GSH-Px; malondialdehyde, MDA) and metal exposure (metallothionein, MT) were estimated in this top predatory mammal. Lead was the most abundant non-essential metal(loid) in both blood and hair, with 4 of 35 individuals having blood levels over 100 μg/L. A positive association was found between Pb level and SOD activity in blood. Free-ranging bears had higher blood SOD activity, Mn, Zn and Cd levels, hair Co, Cd, Tl and Pb compared to captive individuals, while the opposite was true for Mg and hair Ca thereby reflecting habitat and diet differences. With increasing age, animals showed lower levels of SOD activity and certain essential metals. Females had higher SOD activity and blood levels of some essential metals than males. Hair showed a higher Fe and Co level when sampled during the growth phase and was not predictive of non-essential metal(loid) blood levels. The established metal(loid) baseline values will enable future risk assessment in both captive and wild European brown bear populations.
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Affiliation(s)
- Maja Lazarus
- Institute for Medical Research and Occupational Health, Zagreb, Croatia.
| | - Tatjana Orct
- Institute for Medical Research and Occupational Health, Zagreb, Croatia.
| | - Agnieszka Sergiel
- Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland.
| | - Lana Vranković
- Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia.
| | | | - Dubravka Rašić
- Institute for Medical Research and Occupational Health, Zagreb, Croatia.
| | - Slaven Reljić
- Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia.
| | - Jasna Aladrović
- Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia.
| | | | | | - Jasna Jurasović
- Institute for Medical Research and Occupational Health, Zagreb, Croatia.
| | | | - Robert Maślak
- Institute of Environmental Biology, University of Wrocław, Wrocław, Poland.
| | - Nuria Selva
- Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland.
| | - Đuro Huber
- Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland.
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