論文

査読有り
2017年4月

Reproductive parameters and cub survival of brown bears in the Rusha area of the Shiretoko Peninsula, Hokkaido, Japan

PLOS ONE
  • Michito Shimozuru
  • ,
  • Masami Yamanaka
  • ,
  • Masanao Nakanishi
  • ,
  • Jun Moriwaki
  • ,
  • Fumihiko Mori
  • ,
  • Masakatsu Tsujino
  • ,
  • Yuri Shirane
  • ,
  • Tsuyoshi Ishinazaka
  • ,
  • Shinsuke Kasai
  • ,
  • Takane Nose
  • ,
  • Yasushi Masuda
  • ,
  • Toshio Tsubota

12
4
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1371/journal.pone.0176251
出版者・発行元
PUBLIC LIBRARY SCIENCE

servation and management of wildlife. In this study, we investigated the demographic parameters, including age of primiparity, litter size, inter-birth interval, reproductive rate, and cub survival rate, of Hokkaido brown bears (Ursus arctos yesoensis) in the Rusha area on the Shiretoko Peninsula, Hokkaido, Japan, based on a long-term, individual-based monitoring survey. A total of 15 philopatric females were observed nearly every year from 2006 to 2016, and these observations were used to estimate reproductive parameters. The mean age of primiparity was 5.3 +/- 0.2 (SE) years (n = 7, 95% CI = 5.0-5.6). We observed 81 cubs in 46 litters from 15 bears. Litter size ranged from one to three cubs, and averaged 1.76 +/- 0.08 (SE) cubs/litter (95% CI = 1.61-1.91). Inter-birth intervals ranged from 1 to 4 years, and the mean value was estimated as 2.43 (95% CI = 2.16-2.76) and 2.53 (95% CI = 2.26-2.85) years in all litters and in litters that survived at least their first year, respectively. The reproductive rate was estimated from 0.70 to 0.76 young born/year/reproductive adult female, depending on the method of calculation. The cub survival rate between 0.5 and 1.5 years ranged from 60 to 73%. Most cub disappearances occurred in July and August, suggesting that cub mortality is mainly due to poor nutrition in the summer. All reproductive parameters observed in the Rusha area on the Shiretoko Peninsula fell within the range reported in Europe and North America, and were among the lowest or shortest age of primiparity, litter size, and inter-birth intervals, and ranked at a high level for reproductive rate.

Web of Science ® 被引用回数 : 6

リンク情報
DOI
https://doi.org/10.1371/journal.pone.0176251
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000400308800037&DestApp=WOS_CPL