Date: Sat, 25 Oct 2003 12:50:18 EDT Reply-To: Maryland Birds & Birding Sender: Maryland Birds & Birding From: Paul O'Brien Subject: Demise of Ivory Gull? MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Some Ospreyers have seen Ivory Gulls and many more would probably like to see one, especially in Maryland. But that may become impossible in the near future. A very troubling article in the Sept. 26, 2003 issue of Science (Vol. 301, pp. 1840-1) by Kevin Krajick discusses the observations of Canadian Wildlife Service biologist Grant Gilchrist who estimates that IVGU populations in Canada "have plummeted 90% over the past 20 years". Gilchrist was alerted to the problem in 2000 "when Canadian Inuit hunters told researchers that they no longer saw the birds at sea or at town garbage dumps". IVGUs nest on "nunataks--sheer-cliffed islands of rock surrounded by vast glacial icefields--upto 50 kilometers inland from the frozen seas where they scavenge carrion and hunt fish and invertebrates through cracks in the ice". "These hideouts apparently offer chicks protection from predators such as bears and foxes, which can't make the long trek from the sea ice." Three dozen such colonies numbering perhaps 5000 birds were known to be in Canada in the '80s. When Gilchrist and colleagues used planes and helicopters to visit these and a few previously unknown colonies in July of 2002 and 2003 as well as 7000 square kilometers of likely nesting and foraging habitat they found only a few birds. "Their new estimate of the Canadian population: 500 to 700". A Norwegian Polar Institute biologist, Hallvard Strom, in 1996 saw a similar dramatic decline in a portion of the Russian Arctic where the population had been as high as 20,000 birds in the '80s. However, Olivier Gilg of the Arctic Ecology Research Group in Dijon, France, reports that "the 1000 or so birds nesting in east and north Greenland appear to be stable or increasing." Explanations for the decline are not clear. Warming has caused icecaps on the Canadian islands where the gulls nest to shrink 15% to 20% since the 1960s. Some nunataks are no longer isolated and have rejoined the coastal bedrock making it easy for a single fox to walk in and wipe out an entire colony. But the problem could be on the wintering grounds, thought to be the waters between Greenland and Canada. There sea ice has actually increased, disturbing the balance between ice and open water. They may be starving, unable to get at prey in the water. Recent reports of large numbers of IVGUs in Newfoundland in winter could reflect southward displacement in search of food. Shooting by the fast-growing Inuit population in western Greenland is another potential culprit. They also could have moved elsewhere, but that seems a remote hope in view of their strict nesting habitat requirements. Opportunistically speaking, listers should head up to Newfoundland the next time IVGUs are reported. It's much milder than you might expect in winter, and Bruce Mactavish, a great birder, will show you around. Or one could hope that another southern stray like the ones in 1996 near Los Angeles and in Tennessee, might come to Maryland. But don't hold your breath. Instead think about what you, personally, are doing to contribute to global warming. Our collective excessive consumption of fossil fuels is quite likely ringing the death knell for species like Ivory Gull that live on the edge. It is a moral imperative and it makes me sick to see the mindless waste all around me. I could get into specifics, but that is yet another sermon and this is not the right venue. Sorry to be so negative. Paul O'Brien Rockville, Mont. Co., MD pobrien776@aol.com ======================================================================= To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com with the following message in line 1: signoff mdosprey ======================================================================= =========================================================================