- 著者
- Cornelis SWENNEN Yat-tung YU
- 出版者
- The Ornithological Society of Japan
- 雑誌
- ORNITHOLOGICAL SCIENCE (ISSN:13470558)
- 巻号頁・発行日
- vol.3, no.2, pp.119-124, 2004 (Released:2005-07-13)
- 参考文献数
- 17
- 被引用文献数
- 19 9
The bills of the spoonbills differ from the bills of most birds by being wider near the downward curved tip than in the middle, and having the mandibles dorso-ventrally extremely flattened. The mandibles have rounded lateral borders and lack cutting edges. The inward directed sides have a dense cover of thin parallel ridges on the distal parts and rows of teeth-like tubercles in the proximate parts. Their skeletons have numerous small pits in the distal parts especially along the edges and the insides. These pits are similar to the spaces for sensory corpuscles for touch in the bills of Scolopacidae (sandpipers, snipes) and are presumed to have the same function in spoonbills. The bill seems adapted for tactile feeding with lateral movements (sweeping) and for pecking, but not for probing into sediments. The wide gape with gular pouch allows the swallowing of rather large food items. The muscular layer of the gizzard is weakly developed and the gizzard is more a digestive pocket than a chewing organ such as occurs for grinding hard shells and grains in molluscivorous and granivorous birds. The long legs are laterally flattened, perhaps for minimising resistance and not-disturbing prey when walking in water during feeding; the partly webbed feet with long toes allow walking over soft mud bottoms.
- 著者
- Chun-Chiu PANG Yik-Hei SUNG Yun-Tak CHUNG Hak-King YING Hoi-Ning Helen FONG Yat-Tung YU
- 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.81-86, 2023 (Released:2023-01-26)
- 参考文献数
- 34
Our study provides the first GPS tracking data of Little Egret Egretta garzetta from an East Asian population. Our two main objectives were to reveal the migratory route and migratory strategy of Little Egret, and to study inter-annual breeding and wintering site fidelity. Our data, from an adult and a juvenile, suggest that this species is a short-distance high-speed migrant using few or no stopover sites. Both individuals displayed high breeding and wintering site fidelity. They also used very small winter home ranges, probably associated with high prey availability in aquaculture ponds.