Sunday, 11 March 2012

Spoonbill ( Platalea leucorodia )

This spoonbill is listed as Endangered because it has a very small population, split into several small subpopulations, that is believed to be undergoing a continuing decline owing to loss of habitat to industrial development, land reclamation, and pollution. A lack of baseline data makes identifying a population trend problematic, but if the apparent recent increases are confirmed as genuine, the species may warrant downlisting in the future.

Photo by/ Ahmed F.Gad Copyright © 2010
Despite annual censuses indicating year-on-year increases in the population, it is unclear whether these represent genuine increases, displacement of birds from degraded and destroyed sites or simply an increase in observer effort. Therefore, as a precautionary measure, rapid declines are expected to occur in the next ten years.
It breeds in mixed colonies on small islands from March to August. Breeding success is low. It is mainly a crepuscular feeder utilising intertidal mudflats; resting, sleeping and digesting occur at a variety of sites (trees, man-made structure, shallow water) within 2-3 km of feeding areas. Spoonbills employ tactile feeding using lateral sweeps of the bill to locate fish and shrimp prey. Satellite tracking has shown that birds wintering in Hong Kong and Taiwan migrate along the coast of eastern China to northern Jiangsu, then over the Yellow Sea to the Korean peninsula. Wintering birds form large aggregations and it has been recorded amongst flocks of Eurasian Spoonbills Platalea leucorodia. It matures at 5 years of age and birds of at least 9.5 years old have been recorded in the wild.

Photo by/ Ahmed F.Gad Copyright © 2010

 Recent speculation suggests that pollution from pesticides is most congruent with demographic history, in terms of scale and timing of declines and subsequent recovery, as an explantation of past population reduction. However, habitat destruction is probably the biggest threat currently. The main wintering grounds are threatened by industrial development, particularly a key site in Taiwan and also in China, and reclamation, especially in South Korea, Japan and China. Economic development in China has converted many coastal wetlands into aquaculture ponds and industrial estates. Pollution remains a major threat to birds wintering in Hong Kong. An outbreak of botulism at one of the major wintering sites killed 73 birds representing 7% of the world population from December 2002 to February 2003. Increasing levels of disturbance by fishers and tourists and also hunting are threats in China and Vietnam. Fishers in China collect waterbird eggs at nesting sites.

Photo by/ Ahmed F.Gad Copyright © 2010

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

No comments:

Post a Comment