'No hope now remains' for the Alaotra grebe

Jeremy Hance
mongabay.com
May 31, 2010



World governments have missed their goal of stemming biodiversity loss by this year, instead biodiversity loss has worsened according to scientists and policy-makers, and a little rusty-colored bird, the Alaotra grebe (Tachybaptus rufolavatus) is perhaps a victim of this failure to prioritize biodiversity conservation.

Native to a small region in Madagascar, the grebe has been declared extinct by BirdLife International and the IUCN Red List due to several factors including the introduction of invasive carnivorous fish and the use of nylon gill-nets by local fishermen, which now cover much of the bird's habitat, and are thought to have drowned diving grebes. The bird was also poached for food.

"No hope now remains for this species. It is another example of how human actions can have unforeseen consequences", said Dr. Leon Bennun, BirdLife International's Director of Science, Policy and Information. "Invasive alien species have caused extinctions around the globe and remain one of the major threats to birds and other biodiversity."


Illustration of the now extinct Alaotra grebe. Illustration by: Chris Rose.
The last confirmed sighting of the Alaotra grebe was in 1985 on Lake Alaotra. Sightings continued into the late 1980s but the individuals may have been interbreeding with other grebes. Recent surveys found no grebes and, following a final expedition this year, the bird was moved to 'extinct'.

Only one photograph of the bird is known, and unfortunately for posterity it is blurry. Given its rarity, scientists knew little of the species before it vanished. Small wings likely made it incapable of flying far beyond its habitat; it fed on fish; and was usually spotted in pairs. Nothing is known of its breeding ecology or rearing habits.

A recent study has found that freshwater species—like the Alaotra grebe—worldwide are more widely threatened than either land or marine species.

"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," explains Dr. Stuart Butchart, BirdLife International's Global Research and Indicators Coordinator.

The Alaotra grebe is the third grebe to vanish in forty years, and the 132nd bird species to vanish since 1600, although it is likely birds unknown to science also went extinct during that time.

To date 1,240 birds are threatened with extinction according to the IUCN Red List, which added 25 species to the list since last year.

On its website, BirdLife International asked the public whether or not they cared if the Alaotra grebe went extinct given that the species was rare, little-known, and barely studied.

"Yes, I care," wrote one respondent named 'Harry', "grebes are one of my favorite families of birds. A day when you see a grebe is a day which is not completely wasted. And now there’s one less kind in the world. One less source of joy."

Twenty species of grebes—freshwater diving birds—remain; five are threatened with extinction.







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CITATION:
Jeremy Hance
mongabay.com (May 31, 2010).

'No hope now remains' for the Alaotra grebe .

http://news.mongabay.com/2010/0531-hance_alaotragrebe.html