earticle

영어

This study aimed to reveal the genealogical structure and behavioral features using combined datasets of radio-telemetric and genetic analyses in the Asiatic black bear population re-introduced in the Jirisan National Park (JNP), South Korea during their mating seasons since 2008. For each cub, their parents were determined after comparing molecular parentage based on microsatellite genotypes and radio-telemetric records of candidate breeding mothers and fathers during mating seasons. In some cases, without genetic information, we tried parentage analysis using radio-telemetric and direct observation data obtained on-field. The results of this study showed that this bear population has several mating patterns for next generation production. Molecular data showed that both males and females rarely mated with the same parter in different years, thus most consecutive litters were sired by different males. In addition, we found that the some cubs might be made by polyandrous mating from a single litter, and some cubs by polygynous mating between few males and multiple females. Radio-telemetry showed that the home ranges of females have decreased and occupied their own territories after her first delivery. The young females under 3-4 years old after birth, they moved around larger than those of 5 years old after birth after giving the birth of her first cub. Those of males have increased lager after five years old which assumed as the first time of their mating experience than those of under five years old ones, estimating that the males have the mating experience will spend much more time and efforts for seeking breeding partners than those of the young males. We found that the mating trials between male and female have begun from early June and continued to late August. During the mating season, adult males just have approached to female’s home ranges but females did not move toward males to seek for breeding partners. Radio-telemetry showed that the more than a male tried to access an estrous female and stayed nearby her at a time in several mating cases, indicating that the estrous females did not reject the new accesses of strange visiting males in the mating season. This low male-fidelity of the females might be a reason for polyandrous mating in the Asiatic black bear. Recorded coordinates indicated that behavioral patterns of males were mainly discriminated into two different modes. At first males showed area-fidelity rather than female-fidelity. In this pattern, males were found inside or nearby neighboring territories of receptive females for almost mating season, and the males stayed there and contacted sometimes to mate with females for several days in every month of the mating season. After contacting with a female, they moved again to look for another female partner. In addition they came again to mate with the previous female. In this case, the area-fidelity males seem to have a tendency to mate with as many females as possible. On the other hand, a male in this population wandered almost all over the area of JNP and attempted contact with the estrous females for few days, and finally leaved there to go to the next partners. This male also had several cubs as a result of his mating success. All of these accessing and mating behaviors of the males may be contribute to polygynous offspring production. In general females have the rearing delay for the next pregnancy resulting a biennial interval for delivering the next cub. However, in some cases, we also found that some mothers again gave birth to a new cub bear the next year after giving birth to a cub bear. But in this case, the mothers usually released the young cubs. Interestingly, the consanguineous mating between 1st and 2nd generations were also assessed by parentage test, which means whether they could not recognize their parents/cubs or there is no biological barrier for restricting consanguineous mating with their mothers or fathers after sexual maturity. In addition, this phenomenon will be a reason of decreasing the genetic diversity by increasing inbreeding coefficient. Since this bear population is a re-introduced population in the JNP, a decrease in genetic diversity may be one cause of reduced population viability. Our findings concluded that this Asiatic black bear population has various reproduction strategies such as monogamy, polygyny, and multiple mating so on, and the 2nd generation bears born in the JNP have been also participating in mating and breeding for next generation production. The use of the combined datasets of molecular parentage and radio-telemetry will be helpful for providing the critical cues for analyzing mating and behavioral patterns during mating seasons, which will be contribute to better understanding the reproductive biology and behavioral ecology, and to establishing the advanced restoration and management program of the Asiatic black bear in South Korea.