The Red-headed Wood Pigeon Columba janthina nitens is endemic to the Ogasawara Islands, an oceanic island chain located 1000 km south of the main islands of Japan. The subspecies is at high risk of extinction because of its small population size and restricted habitat range. We undertook genetic analyses of this pigeon using sequences of a portion of the mitochondrial control region and five microsatellite markers to estimate the genetic characteristics of two wild populations from the Bonin and Volcano Islands, as well as one captive breeding population. The genetic diversity of the wild individuals was exceptionally low in both the mitochondria (nucleotide diversity = 0.00105) and at the microsatellite (3.2 alleles per locus and H E = 0.12) loci. Higher numbers of microsatellite genotypes were observed in the Volcano Islands population than in the Bonin Islands population, which may be because of the relatively low impact of human disturbance. The most common mitochondrial haplotypes and microsatellite alleles observed in the two wild populations were completely fixed in the captive population. Our results suggest that the genetic diversity of the captive population needs to be increased. However, introduction of a wild individual into a captive population can lead to a decreased genetic diversity in the wild population and therefore should be done with caution. The genetic differentiation between the Bonin and the Volcano island groups was low, and the populations of the two island groups should be regarded as a single evolutionarily significant unit. However, special consideration is required for habitat conservation in the Volcano Islands, which may be functioning as a sanctuary for the Red-headed Wood Pigeon. For the long-term conservation of threatened bird species that live on remote oceanic islands, determination of management units considering gene flow caused by their flying capacity and maintenance of genetically suitable wild and captive populations are essential.

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Identification of the sex of birds is important for captive breeding of endangered species. In the oriental white stork (Ciconia boyciana), an endangered species, both sexes produce an acoustic signal called "clatter" by rattling their mandibles together to generate sounds. We examined the structure of male and female clatter to determine whether clatter is sexually dimorphic. The acoustic structure of the clatter of the two sexes proved to be dimorphic with respect to the fundamental frequency; female clatter had higher fundamental frequencies. The fundamental frequency correlated significantly and positively with bill length, suggesting that bill morphology contributes to the sexual dimorphism of clatter. Sexing can be done by acoustic signals without capturing birds, and thus is useful as a non-invasive sexing method for ecological and conservation studies of birds.

2 A 24 HSRVII) ?V-A"90iz'ftsI# Ere)iCHR i), ne)ZIHSs!,! Z), flxlilws-3) 1) matLF'i,Mvasuiz)f-9-i24].0804 pmAJI[veuaDltiJg[IIJ[[#tla'MI 155-1 z) waata/i"A l･ISSigittzmu i 241-oool t4if,EMvaIfi"trlrfimaX.t.FltNUy ll7s-1 3) .gpafu#tuUpa i 191-O042 HIJJ;'glSH!irftUe,t71 7-1-1 ABSTRACT. For the geneLic managemeni or capt.ive Asian tapir, geneLic variation of captive indjviduals was investigated using mitochondrial cytochrorno b scquencing. We t'ound two genetic lines/ the Indonesian captiviLy and Malay Peninsu[a captivity lines, This finding indicates that the Asian tapir rnight have difi/erentiated into two geogi'aphic groups, name!y, the Sumatra Island and Malay Peninsula groups, This biogeograpbic diff{/rent.iation is also observed in other maminals iri this area, Key wordsi Asian Lapir, capLive conservation, mitochoridrial cytochrome b

No abstract