Thursday, March 25, 2010

Herring Gull Makes Round Trip

Who would have thought that herring gulls would be a harbinger of spring!?

One of the herring gulls tagged last spring on Kent Island, a small island off the coast of Grand Manan Island has completed a round trip from Kent Island to the Chesapeake Bay area and back. The bird was one of three that were fitted with satellite transmitters to follow their movements in the Bay of Fundy. The added benefit is that all three birds were migratory, spending the winter in Chesapeake Bay area. Normally this would be a great place for a herring gull but the area was plagues with severe winter storms this year. The other two birds have not returned yet and we wait to see if they will show site fidelity and nest again on Kent Island. the tracks of all three birds can be found at http://www.seaturtle.org/tracking/index.shtml?project_id=428.

Of the nine greater shearwaters fitted with satellite tags last summer, only two remain transmitting, over 200 days of data. The failure of the tag is often the battery but sometimes the birds die. One tag transmitter for several weeks from Inaccessible Island in the South Atlantic where shearwaters nest. it is suspected that the bird was prey to a skua, a large predatory seabird, which patrol the nesting colonies. We also had a transmitter returned last year from a Brazilian fisherman who had caught the shearwater on longlines. Bycatch in fisheries can be a major factor in seabird mortality. The birds are attracted to the baited hooks and can not see the hook. Surface drift nets may also entangle large numbers of seabirds. There are efforts in some areas to reduce the bycatch but it is still a problem in some areas. The tracks of the greater shearwaters can be seen at http://www/seaturtle.org/tracking/?project_id=435

Rob Ronconi, one of our seabird biologists, spent three months in the South Atlantic last fall including time on both Gough and Inaccessible Islands. He helped tag 22 nesting or pre-nesting greater shearwaters. The birds have been wide ranging from South America to South Africa in the same areas that the birds we have tagged from the summer in the Bay of Fundy also range once they reach the South Atlantic. Although four tags have failed, it is hoped that the tags last long enough that the northward migration may be captured as well as the forging in the South Atlantic. These tracks can be viewed at http://www.seaturtle.org/tracking/index.shtml?project_id=452

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