Reported mating of Hokkaido brown bear in autumn

Kohira, Masao; Mori, S.

doi:10.2192/09sc030.1

Cited by 8 publications

(8 citation statements)

References 11 publications

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“…This phenomenon was also reported in other brown bear populations [25, 34, 35]. In the Rusha area, copulatory behavior was reported in October [36], outside of the normal breeding season for brown bears (late spring to early summer [37]), which may have led to the consecutive births.…”

Section: Resultssupporting

confidence: 65%

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

et al. 2017

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Knowing the reproductive characteristics of a species is essential for the appropriate conservation 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.

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Section: Resultssupporting

confidence: 65%

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

et al. 2017

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“…mating season, well into autumn (Nevin & Gilbert 2005;Kohira & Mori 2010;Tosoni et al 2011;Steyaert et al 2012).…”

Section: Resultsmentioning

confidence: 99%

Polar bears (Ursus maritimus) mating during late June on the pack ice of northern Svalbard, Norway

Smith¹,

Aars

2015

Polar Research

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Polar bears are seasonal breeders and typically mate from late March to early May. Implantation is, however, delayed until autumn, which can allow plasticity in the date of mating. As for other seasonal breeders, a rapid return to estrus after the loss of dependent offspring can be expected, even into the summer. A few earlier observations and dissections of dead animals suggest that polar bears are able to mate in summer. We report on a mating incident on 29 June 2014, the first documented mating this late in the season among wild polar bears. The female had lost her dependent cub during the period prior to the mating event. We speculate that she lost this cub late in the mating season, entered estrus and successfully mated in late June.

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“…Most observations of bear mating behavior have been acquired by chance from wild populations and thus provide incomplete descriptions (Mundy and Flook 1964, Sparrowe 1968, Herrero and Hamer 1977, Nevin and Gilbert 2005, Kohira and Mori 2010. Others are difficult to interpret due to the way in which data were collected (e.g., 'frames' ;Ludlow 1976) or reported (e.g., seconds as units for mount; Boone et al 2003).…”

Section: Discussionmentioning

confidence: 99%

“…All successful mount durations in our study occurred within the range of successful wild brown bear mount durations reported by Craighead et al (1995). The average successful (Ludlow 1976) and free-ranging American black bears and brown bears (Mundy and Flook 1964, Sparrowe 1968, Herrero and Hamer 1977, Kohira and Mori 2010 Table 2). In contrast, the average mount duration of presumably successful mounts (included quivering) previously reported on the same semi-free ranging population (Boone et al 2003) was similar to the average unsuccessful mount duration from our study.…”

Section: Discussionmentioning

confidence: 99%

“…However, specific data on intromission duration and frequency were not included, and although latency between quivers was mentioned, actual quiver durations and frequencies were not (Ludlow 1976). Other reports (Mundy and Flook 1964, Sparrowe 1968, Herrero and Hamer 1977, Nevin and Gilbert 2005, Kohira and Mori 2010 were chance observations of wild bears providing what information the authors were able to collect.…”

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confidence: 99%

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