International: Wetland aliens cause bird extinction

25 May 2010

In the 2010 IUCN Red List for birds, the Madagascan bird, Alaotra Grebe Tachybaptus rufolavatus has been listed as extinct.

The bird has been restricted to a tiny area in East Madagascar and became victim to a carnivorous fish that was introduced into its lake-habitat.

Their numbers have also been depleted by fishers in the area who would also use nylon nets which led to fatal entanglements.

Another wetland species suffering from the impacts of introduced aliens (mongoose and exotic catfish) is Zapata Rail Cyanolimnas cerverai from Cuba. It has been uplisted to Critically Endangered.

Likewise in Asia and Australia, numbers of once common wader species such as Great Knot Calidris tenuirostris and Far Eastern Curlew Numenius madagascariensis are dropping rapidly as a result of drainage and pollution of coastal wetlands.

The destruction of inter-tidal mudflats at Saemangeum in South Korea, an important migratory stop-over site, correlated to a 20% decline in the world population of Great Knot. Huge flocks of these birds once visited northern Australia, but annual monitoring by scientists have found corresponding declines in numbers.

“Wetlands are fragile environments, easily disturbed or polluted, but essential not only for birds and other biodiversity but also for millions of people around the world as a source of water and food”, said Dr Stuart Butchart, BirdLife's Global Research and Indicators Coordinator.

On a more positive note, the Azores Bullfinch Pyrrhula murina has been downlisted from Critically Endangered to Endangered as a result of conservation work to restore natural vegetation on its island home. SPEA (BirdLife in Portugal) and RSPB (BirdLife in the UK) have worked together with others to turn around the fortunes of this species in what is a model for other projects.