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Careddu G, Ciucci P, Mondovì S, Calizza E, Rossi L, Costantini ML. Gaining insight into the assimilated diet of small bear populations by stable isotope analysis. Sci Rep 2021; 11:14118. [PMID: 34238974 PMCID: PMC8266819 DOI: 10.1038/s41598-021-93507-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/24/2021] [Indexed: 12/02/2022] Open
Abstract
Apennine brown bears (Ursus arctos marsicanus) survive in an isolated and critically endangered population, and their food habits have been studied using traditional scat analysis. To complement current dietary knowledge, we applied Stable Isotope Analysis (SIA) to non-invasively collected bear hairs that had been individually recognized through multilocus genotyping. We analysed carbon (δ13C) and nitrogen (δ15N) stable isotopes of hair sections and bear key foods in a Bayesian mixing models framework to reconstruct the assimilated diet on a seasonal basis and to assess gender and management status effects. In total, we analysed 34 different seasonal bear key foods and 35 hair samples belonging to 27 different bears (16 females and 11 males) collected during a population survey in 2014. Most bears showed wide δ15N and δ13C ranges and individual differences in seasonal isotopic patterns. Vegetable matter (herbs, fleshy fruits and hard mast) represented the major component of the assimilated diet across the dietary seasons, whereas vegetable crops were rarely and C4 plants (i.e., corn) never consumed. We confirmed an overall low consumption of large mammals by Apennine bears consistently between sexes, with highest values in spring followed by early summer but null in the other seasons. We also confirmed that consumption of fleshy fruits peaked in late summer, when wild predominated over cultivated fleshy fruits, even though the latter tended to be consumed in higher proportion in autumn. Male bears had higher δ 15N values than females in spring and autumn. Our findings also hint at additional differences in the assimilated diet between sexes, with females likely consuming more herbs during spring, ants during early summer, and hard mast during fall compared to males. In addition, although effect sizes were small and credibility intervals overlapped considerably, management bears on average were 0.9‰ lower in δ 13C and 2.9‰ higher in δ 15N compared to non-management bears, with differences in isotopic values between the two bear categories peaking in autumn. While non-management bears consumed more herbs, wild fleshy fruits, and hard mast, management bears tended to consume higher proportions of cultivated fruits, ants, and large mammals, possibly including livestock. Although multi-year sampling and larger sample sizes are needed to support our findings, our application confirms that SIA can effectively integrate previous knowledge and be efficiently conducted using samples non-invasively collected during population surveys.
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Affiliation(s)
- Giulio Careddu
- Department of Environmental Biology, Sapienza University of Rome, Rome, Italy
| | - Paolo Ciucci
- Department of Biology and Biotechnologies "Charles Darwin", Sapienza University of Rome, Rome, Italy.
| | - Stella Mondovì
- Department of Environmental Biology, Sapienza University of Rome, Rome, Italy.,Department of Biology and Biotechnologies "Charles Darwin", Sapienza University of Rome, Rome, Italy
| | - Edoardo Calizza
- Department of Environmental Biology, Sapienza University of Rome, Rome, Italy
| | - Loreto Rossi
- Department of Environmental Biology, Sapienza University of Rome, Rome, Italy
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Jimbo M, Matsumoto N, Sakamoto H, Yanagawa Y, Torii Y, Yamanaka M, Ishinazaka T, Shirane Y, Sashika M, Tsubota T, Shimozuru M. Hair Growth in Brown Bears and Its Application to Ecological Studies on Wild Bears. MAMMAL STUDY 2020. [DOI: 10.3106/ms2020-0021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Mina Jimbo
- Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan
| | - Naoya Matsumoto
- Noboribetsu Bear Park, 224 Noboribetsuonsencho, Noboribetsu, Hokkaido 059-0515, Japan
| | - Hideyuki Sakamoto
- Noboribetsu Bear Park, 224 Noboribetsuonsencho, Noboribetsu, Hokkaido 059-0515, Japan
| | - Yojiro Yanagawa
- Department of Clinical Sciences, Division of Veterinary Medicine, Faculty of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan
| | - Yoshiko Torii
- Department of Clinical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan
| | - Masami Yamanaka
- Shiretoko Nature Foundation, 531 Iwaubetsu, Shari, Hokkaido 099-4356, Japan
| | | | - Yuri Shirane
- Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan
| | - Mariko Sashika
- Department of Environmental Veterinary Sciences, Division of Veterinary Medicine, Faculty of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan
| | - Toshio Tsubota
- Department of Environmental Veterinary Sciences, Division of Veterinary Medicine, Faculty of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan
| | - Michito Shimozuru
- Department of Environmental Veterinary Sciences, Division of Veterinary Medicine, Faculty of Veterinary Medicine, Hokkaido University, Kita 18 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-0818, Japan
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Ueda M, Bell LS. Assessing dual hair sampling for isotopic studies of grizzly bears. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34:e8572. [PMID: 31916335 DOI: 10.1002/rcm.8572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
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