著者

Yuji OKAHISA Yoshinori KANEKO Hisashi NAGATA Kiyoaki OZAKI

出版者

The Ornithological Society of Japan

雑誌

ORNITHOLOGICAL SCIENCE (ISSN:13470558)

巻号頁・発行日

vol.21, no.2, pp.145-154, 2022 (Released:2022-08-13)

参考文献数

48

被引用文献数

1

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An increasing number of reintroduction programs have been set up in recent years in an attempt to reintroduce once extinct species to their indigenous ranges and create self-sustaining populations. However, the released individuals often experience low mating success and fecundity. Appropriate rearing in captivity is considered essential for the successful post-release reproduction of captive-reared individuals. Low post-release mating success and fecundity are also issues in reintroduced Crested Ibis Nipponia nippon populations on Sado Island. These phenomena may be caused by the effects of hand-rearing in captivity, yet temporary hand-rearing is necessary when captive breeding, because rescuing embryos from mortality is essential due to the abnormal behavior of parent birds in captivity. Therefore, the establishment of rearing methods that temporarily protect embryos or chicks while limiting the negative effects of hand-rearing on breeding after release is needed. To overcome these challenges, we tested how captive rearing methods impact post-release courtship behavior, mating success, and fecundity of the ibis. By combining detailed rearing history in captivity with long-term post-release monitoring, we demonstrate that the initiation of parental rearing before the chicks' eyes open is the critical factor leading to increased pseudocopulation frequency and mating success in captive-born male ibis. Based on these results, not hand-rearing the chicks beyond the day after hatching would reduce the impact of hand-rearing on reproduction after release. Rearing methods that take into account the nestling period should be implemented to enhance the efficiency and reduce the cost of avian reintroduction projects.

著者

Yuichi Wajiki Yoshinori Kaneko Toshie Sugiyama Takahisa Yamada Hiroaki Iwaisaki

出版者

日本家禽学会

雑誌

The Journal of Poultry Science (ISSN:13467395)

巻号頁・発行日

pp.0150040, (Released:2015-08-25)

被引用文献数

2

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The Japanese captive population of Japanese crested ibis (Nipponia nippon) was established using 5 founders derived from the Chinese captive population. Its size has increased rapidly, and the maintenance phase is about to start. Thus, this study was designed to perform genetic analyses in this population with pedigree information, considering the adoption of mean kinship strategy as the breeding strategy suited to the maintenance phase. Because the relationships among the 5 founders were unknown, different assumptions were set up ranging from 0 to 0.25 of kinship coefficients between the 5 founders. Assuming that the 5 founders were non-inbred in all the assumptions, the results showed that the gene diversity and the mean inbreeding coefficient would fluctuate largely from ∼65% to ∼82% and from ∼0.07 to ∼0.29, respectively. Moreover, the genetic importance of individuals based on mean kinship shifted largely. This study suggested that the Japanese captive population had low gene diversity and high mean inbreeding coefficient even under the assumption that the 5 founders were unrelated and non-inbred. In addition, the study also suggested that it became more effective to analyze the genetic status and to introduce mean kinship strategy into this population with more credible molecular evaluation of the relationships among founders.