Marine National Park Headquarters

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Key word: Dongsha Atoll National Park, migrant birds, White-breasted Waterhen

Dongsha Atoll National Park is located at northern region of the South China Sea, in the middle part of the East Asia–Australia bird migration route. Dongsha island is a permanent landmass with diverse habitats, including woodlands, bushes, lagoons, and beaches, which provide excellent stopover habitats for migrating birds en route. According to previous surveys, Dongsha island has 270 species of birds, including the only resident bird species, the White-breasted Waterhen Amaurornis phoenicurus. The project of 2015 conducted a year round study on 1) the reproductive ecology of resident species, 2) stopover ecology of migrant species, and 3) taking photos on birds and their habitats. A total of 212 bird species were recorded in this year’s survey, including 14 newly recorded species, and it pushed the species list up to 284 species. The passage of most migrants showed multiple peaks during migration seasons, and the amounts of passage were different between spring and fall migration. In addition, Dongsha island was found to be an important harbor to many sea and shore birds during typhoon period. Biodiversity indices indicated that spring and fall had higher species richness, and the least in summer. The most dominant species at the island was the Ruddy Turnstone (Arenaria interpres), and the most widespread species was the Barn Swallow (Hirundo rustica). The plot with the highest migrant species was located in the pond near runway. Four banding operations caught 148 birds and sighted 201 birds with leg flag, and 4 of them came from Tasmania Island, 7200 km away from Dongsha island. Twelve playback trials on the response of breeding pairs of White-breasted Waterhens were carried out at 54 points, and 46 breeding pairs were identified. The waterhens almost spread all over the island, and expanded even further into the mouth of the lagoon compared to last year's survey. According to camera recording, average fledgling number was 2.8±1.9 chicks (n = 21), and 4 breeding pairs apparently produced second broods. Preliminary analysis of Mitochondrion DNA of 10 banded waterhens did not show any difference from samples from near regions such as Taiwan, India, and Japan. Further banding operations are necessary to illustrate the status of waterhens at Dongsha island either through microsatellite DNA analysis or applying radio transmitters or geolocators to track their dispersal pattern after breeding season. Conservation applications are suggested in the followings: 1) management of dogs during bird migration period, 2) providing waterbaths, 3) reducing expansion of mangrove forest, 4) shifting of military exercise during bird migration period, 5) control of rat population.

Published: Mar 16,2016