- 著者
- Haruna SAKAMOTO Daisuke AOKI Shingo UEMURA Masaoki TAKAGI
- 出版者
- The Ornithological Society of Japan
- 雑誌
- ORNITHOLOGICAL SCIENCE (ISSN:13470558)
- 巻号頁・発行日
- vol.22, no.1, pp.45-56, 2023 (Released:2023-01-26)
- 参考文献数
- 54
Negative relationships between the degree of parental investment and the presence of unrelated offspring in the nest due to extra-pair paternity (EPP) or conspecific brood parasitism (CBP) are predicted in monogamous species. This is because investing in unrelated offspring is costly to individual parents. However, such strategies may be adaptive for one social partner. Because parental investment changes in response to that by the social partner, the predicted relationship needs to be assessed empirically in wild animal populations, with consideration for male and female parental care. Furthermore, both EPP and CBP must be considered simultaneously in such a study. In this study, we tackled the issue using the semi-colonial Eurasian Tree Sparrow Passer montanus, in which both EPP and CBP were predicted to occur. We tested whether there is a negative relationship between the degree of parental care of both males and females and the presence of EPP or CBP, taking into consideration the parental investment of their social partners, using behavioral observations and parentage analyses based on seven microsatellite loci. The results revealed a moderately high frequency of EPP and CBP within a sparrow colony. A negative relationship between parental care by the social male parent and the presence of EPP was suggested, while this was possibly as a result of the increase in parental investment by their female partner. CBP was also inferred to be linked with male parental investment, while females may have compensated for the cost of CBP in their provisioning efforts by egg rejection. High frequencies of occurrence of both EPP and CBP allowed us to shed light on how parental investment is related to the presence of unrelated young in the complex social system of the Eurasian Tree Sparrow.
- 著者
- Akira SAWADA Tetsuya IWASAKI Chitose INOUE Kana NAKAOKA Takumi NAKANISHI Junpei SAWADA Narumi ASO Syuya NAGAI Haruka ONO Ryota MURAKAMI Masaoki TAKAGI
- 出版者
- The Ornithological Society of Japan
- 雑誌
- ORNITHOLOGICAL SCIENCE (ISSN:13470558)
- 巻号頁・発行日
- vol.22, no.1, pp.25-34, 2023 (Released:2023-01-26)
- 参考文献数
- 42
- 被引用文献数
- 1
Empirical ornithologists often analyse dispersal distance by histograms separately drawn for categories of individuals (e.g., sexes), and/or by linear models with normal distribution (e.g., ANOVA). However, theoreticians describe dispersal distance by dispersal kernels with various parametric distributions. Therefore, it is a helpful exercise for empiricists to estimate dispersal kernels from field data. As a model case for such an estimation, we analysed dispersal data of the Ryukyu Scops Owls Otus elegans using a Bayesian Weibull regression model. Estimated dispersal kernels showed that males and individuals fledged from late-breeding nests had short natal dispersal distances and that no factors affected breeding dispersal significantly.
- 著者
- Masaoki Takagi Kana Akatani
- 出版者
- The Ornithological Society of Japan
- 雑誌
- ORNITHOLOGICAL SCIENCE (ISSN:13470558)
- 巻号頁・発行日
- vol.10, no.2, pp.151-156, 2011 (Released:2012-04-06)
- 参考文献数
- 18
- 被引用文献数
- 6
We identified the diet of owlets of the Daito subspecies of the Ryukyu Scops Owl Otus elegans interpositus on Minami-daito Island during late May and early June 2009, by means of high-resolution color photography. Cockroaches were provided by parents to their young at all eight nests studied, and contributed the largest single component of the diet (33%). Orthoptera species, which inhabited open grassland habitats, constituted >20% of the total occurrences in the diet of owlets. It is suggested that Ryukyu Scops Owls depend heavily on food items obtained from habitats that have been modified by human activity on Minami-daito Island. Diets for owlets differed widely among nests, and the differences were considered to result from individual differences among parents and/or the environments surrounding each nest.
- 著者
- Masaoki Takagi Takema Saitoh Noriyuki Yamaguchi Hiroto Okabe Isao Nishiumi Masayoshi Takeishi
- 出版者
- 日本鳥学会
- 雑誌
- ORNITHOLOGICAL SCIENCE (ISSN:13470558)
- 巻号頁・発行日
- vol.14, no.1, pp.53-59, 2015 (Released:2015-02-18)
- 参考文献数
- 19
- 被引用文献数
- 7
A nest of the Ryukyu Scops Owl Otus elegans was found on Okinoshima (Okino Island), Fukuoka Prefecture, Japan (34.24°N, 130.10°E), in the Tsushima Strait, on 28 July 2013. The breeding pair and their three owlets were caught and their identity confirmed genetically using the BOLD System for COI in the mitochondrial genome. Their calls and external morphological measurements also accorded with what is known of the species. We estimated that at least 23 territorial males inhabit the Island. Okinoshima lies 490 km beyond the previously known northern limit of the species' distribution.