BREEDING ECOLOGY AND HABITAT USE OF THE DAITO SCOPS OWL (OTUS ELEGANS INTERPOSITUS) ON AN OCEANIC ISLAND

作者：Akatani Kana^*; Matsuo Taro; Takagi Masaoki

来源：Journal of Raptor Research, 2011, 45(4): 315-323.

DOI：10.3356/JRR-10-82.1

• Daito Scops Owl
• Otus elegans interpositus
• Elegant Scops Owl
• breeding
• Casuarina
• development
• fragmented habitat
• island
• nest

We studied the nest sites, diet, and habitat use of the endemic population of the Daito Scops Owl (Otus elegans interpositus), a subspecies of the Elegant Scops Owl (O. elegans), on a small oceanic island, Minami-daito, in the northwestern Pacific Ocean. We also investigated the relationships between habitat characteristics and breeding performance in the fragmented and developed habitats on the island. Most owls used nest cavities in introduced casuarina (Casuarina spp.) trees (n = 30), whereas a few owls used vertical hollows in broken native fan palm (Livistona chinensis; n = 2) as their nest sites. Owls fed on prey inhabiting both forests and open areas, including spiders (Heteropoda), cockroaches (Blattodea), grasshoppers (Orthoptera) and geckos (Gekkonidae). We tracked 17 territorial males and seven females using radiotelemetry in 2002-07. More than half of the owls selected Fins forests during the breeding season. During the nonbreeding season, most owls selected edges between forests and open areas such as grass-lands and sugar cane fields. Owls with more edge habitat within their home ranges laid eggs earlier (n = 88 breeding attempts) than those with smaller amounts of edge. Daito Scops Owls exhibited behavioral flexibility in their use of human-altered habitats on Minami-daito Island, which may have contributed to their avoidance of extinction.

• 出版日期2011-12