Sat, May 9, 2009

Seabirds are dying in large numbers yet again

By Barry Parr on Sat, May 9, 2009

Tom Grey

Brandt's Cormorants seem to be the most common victims of this unexplained mortality event.

Tom Grey

Common Loons are also being found on beaches.

Tom Grey

13 Western Grebes were found dead at Ocean Beach in San Francisco. Photo

Tom Grey

The San Francisco Bay Area usually supports both Double-crested (left) and Brandt's (right) Cormorants in large numbers.

Seabirds are once again dying along the coast from San Francisco as far South as Oxnard, according to WildCare.

Brandt’s Cormorants, grebes and loons are those that seem to be most commonly found. The largest numbers of dead birds reported so far include 67 Brandt’s and 13 grebes at Ocean Beach. This event seems to have coincided with the large wind storms that came through around April 15 but no one knows if that’s relevant.

So far preliminary necropsy findings show emaciation as the only issue that some of the dead birds had in common BUT many of the dead birds have been within normal healthy body weights.

However, IBRRC (the International Bird Rescue and Research Center) reports that of the over 30 live birds they have treated all were emaciated and had very heavy parasite loads and low blood levels. The birds ate well, were treated for the parasites and were banded and released when healthy.

Lab results on May 4 were negative for Avian Influenza, West Nile Virus, Newcastle Disease and domoic acid poisoning.