Effective Dispersal of Brown Bears (<i>Ursus arctos</i>) in Eastern Hokkaido, Inferred from Analyses of Mitochondrial DNA and Microsatellites

Itoh, Toshiya; Sato, Yoshikazu; Kobayashi, Kyoko; Mano, Tsutomu; Iwata, Ryûtarô

doi:10.3106/041.037.0104

Cited by 12 publications

(9 citation statements)

References 59 publications

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“…As revealed by previous studies, paternity results are credible when PE I and PE II values exceeded 99.9% and 99%, respectively [14,23,24,25,26]. In this study, PE I and PE II values were 99.99% and 99.93%, respectively, indicating that the 21 microsatellite loci we used were appropriate for parentage analysis.…”

Section: Discussionsupporting

confidence: 74%

Parentage-Based Group Composition and Dispersal Pattern Studies of the Yangtze Finless Porpoise Population in Poyang Lake

Chen

Zheng

Hao

et al. 2016

IJMS

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Social behaviors are poorly known for the critically endangered Yangtze finless porpoise (YFP, Neophocaena asiaeorientalis asiaeorientalis). Here, group composition and dispersal patterns of the YFP population living in the Poyang Lake were studied by parentage-based pedigree analyses using 21 microsatellite loci and a 597 bp segment of the mitochondrial DNA control region. In this study, 21 potential mother-offspring pairs and six potential father-offspring pairs (including two potential parents-offspring pairs) were determined, among which 12 natural mother-offspring groups and a maternal group of three generations were found. No genetically-determined fathers were found associated with their offspring. This study also found that maternally related porpoises at the reproductive state tend to group together. This suggest maternal relationship and reproductive state may be factors for grouping in the YFP population. In natural mother-offspring groups, male offspring were all younger than two years old, which suggest male offspring may leave their mothers at approximately two years of age, or at least they were not in tight association with their mothers as they may have been under two years old. However, female offspring can stay longer with their mothers and can reproduce in the natal group.

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Section: Discussionsupporting

confidence: 74%

Parentage-Based Group Composition and Dispersal Pattern Studies of the Yangtze Finless Porpoise Population in Poyang Lake

Chen

Zheng

Hao

et al. 2016

IJMS

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“…These males were probably individuals that had dispersed from their natal area during a single generation. Other studies [ 53 , 54 ] using a combination of mtDNA and autosomal microsatellite markers have also demonstrated dispersal of extant males as well as male-mediated gene flow between natal areas defined by mtDNA lineages (the southern Akan-Shiranuka region, central and eastern Hokkaido). These signs of male-mediated gene flow among populations reiterate that the distinct maternal phylogeographic structure on Hokkaido Island has been maintained by strong female philopatric behavior, despite fairly common male immigration between maternal populations.…”

Section: Discussionmentioning

confidence: 99%

Paternal phylogeographic structure of the brown bear (Ursus arctos) in northeastern Asia and the effect of male-mediated gene flow to insular populations

et al. 2017

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Background Sex-biased dispersal is widespread among mammals, including the brown bear ( Ursus arctos ). Previous phylogeographic studies of the brown bear based on maternally inherited mitochondrial DNA have shown intraspecific genetic structuring around the northern hemisphere. The brown bears on Hokkaido Island, northern Japan, comprise three distinct maternal lineages that presumably immigrated to the island from the continent in three different periods. Here, we investigate the paternal genetic structure across northeastern Asia and assess the connectivity among and within intraspecific populations in terms of male-mediated gene flow. Results We analyzed paternally inherited Y-chromosomal DNA sequence data and Y-linked microsatellite data of 124 brown bears from Hokkaido, the southern Kuril Islands (Kunashiri and Etorofu), Sakhalin, and continental Eurasia (Kamchatka Peninsula, Ural Mountains, European Russia, and Tibet). The Hokkaido brown bear population is paternally differentiated from, and lacked recent genetic connectivity with, the continental Eurasian and North American populations. We detected weak spatial genetic structuring of the paternal lineages on Hokkaido, which may have arisen through male-mediated gene flow among natal populations. In addition, our results suggest that the different dispersal patterns between male and female brown bears, combined with the founder effect and subsequent genetic drift, contributed to the makeup of the Etorofu Island population, in which the maternal and paternal lineages show different origins. Conclusions Brown bears on Hokkaido and the adjacent southern Kuril Islands experienced different maternal and paternal evolutionary histories. Our results indicate that sex-biased dispersal has played a significant role in the evolutionary history of the brown bear in continental populations and in peripheral insular populations, such as on Hokkaido, the southern Kuril Islands, and Sakhalin. Electronic supplementary material The online version of this article (10.1186/s40851-017-0084-5) contains supplementary material, which is available to authorized users.

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“…A brown bear subpopulation inhabits the Akan‐Shiranuka region of eastern Hokkaido, Japan. Serious human–bear conflicts occur in the southern periphery of the region, near the town of Urahoro (Sato et al ., ; Itoh et al ., ). The number of bears killed in recent years in Urahoro by lethal control (mainly using cage traps) has been increasing (Sato et al ., ).…”

Section: Methodsmentioning

confidence: 97%

“…The core area located in the center of the subpopulation is in the forested areas and is far from human settlements, whereas the periphery is close to human settlements and contains a number of agricultural crop fields. Studies on the mtDNA haplotypes of female bears in the Akan‐Shiranuka region indicate that different haplotypes are distributed allopatrically between the core area and the southern periphery in the subpopulation (Sato et al ., ; Itoh et al ., ). The bear density in this subpopulation has decreased and their dependency on crops as food sources has increased (Sato et al ., ).…”

Section: Methodsmentioning

confidence: 97%

Stable isotope and DNA analyses reveal the spatial distribution of crop‐foraging brown bears

et al. 2017

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We investigated maize (Zea mays) consumption by brown bears (Ursus arctos) in a subpopulation of eastern Hokkaido, Japan, using carbon stable isotope analysis of hair samples to better understand the pattern and scale of movement of the bears' crop-foraging behavior. We identified a total of 30 individuals (19 males and 11 females) using DNA analysis of the hair samples. Stable isotope analysis suggested that female bears that were more likely to consume maize lived closer to agricultural crop fields. Our statistical model also estimated that the relative maize consumption of female bears decreased rapidly as the distance to crop fields increased to 3-4 km, similar to the radius of the annual home range of female bears. In contrast, male bears that were more likely to consume maize lived both in forested areas and near crop fields. Even if male bears live in a forested area except during the maize harvest period, they appeared to be at risk of being killed by lethal control because they can move from forested areas to crop fields during the maize harvest period. Collecting hair samples of many bears in the population over several years may allow the effect of lethal control on population viability to be estimated non-invasively.

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Effective Dispersal of Brown Bears (Ursus arctos) in Eastern Hokkaido, Inferred from Analyses of Mitochondrial DNA and Microsatellites

Cited by 12 publications

References 59 publications

Parentage-Based Group Composition and Dispersal Pattern Studies of the Yangtze Finless Porpoise Population in Poyang Lake

Parentage-Based Group Composition and Dispersal Pattern Studies of the Yangtze Finless Porpoise Population in Poyang Lake

Paternal phylogeographic structure of the brown bear (Ursus arctos) in northeastern Asia and the effect of male-mediated gene flow to insular populations

Stable isotope and DNA analyses reveal the spatial distribution of crop‐foraging brown bears

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