LAGRANGE, Ga. -- The rare bird that attracted hundreds of bird lovers to West Point Lake last month died of acute aspergillosis, an infection caused by the growth of a specific type of fungus.
The Ivory Gull, whose habitat is typically in the Arctic area, was spotted at the lake last month and captivated visitors for days before it died.
Steve Holzman, of the U.S. Fish and Wildlife Service, said in an e-mail that a necropsy conducted at the Southeastern Cooperative Wildlife Disease Study at the University of Georgia revealed the bird had aspergillosis.
Holzman said it was also evident the bird was thin but not emaciated and there were no signs of physical injury, contrary to reports from visitors that the bird had a broken wing. He also reported the doctor conducting the necropsy said the gull's recovery, even if it had been captured, would have been unlikely due to the severity of the infection.
David Barr, U.S. Army Corps of Engineers ranger at West Point Lake, said once the bird is mounted it will be returned to the lake, where it will be on display for about three months. Barr said currently the bird is at a taxidermist in Atlanta. He estimates it will be returned to the lake some time next month. It will be displayed in the West Point Lake Visitors Center.
According to information posted online by the New York Department of Conservation's Wildlife Pathology Unit, the spores that cause aspergillosis are everywhere, so a bird often is exposed to them, but its immune system usually fights off infection.
"The chronic form of the aspergillosis generally occurs in birds that have been weakened and stressed by malnutrition, injury, other disease, or exposure to toxicants.... Chronic aspergillosis typically starts as small plaques on air sac walls," the pathologists report. "Plaques may grow, coalesce and completely cover the interior lining of air sacs. They may also form large rubbery masses that envelop blood vessels, particularly in the vicinity of the heart. Mature lesions often include sites of spore production, manifested by a dusty-looking, gray-blue-green surface; i.e. looks like fruiting mold on spoiled food. Despite the fairly long-term growth in parts of the respiratory tract, actual lung involvement seems to occur only in the terminal phase of disease progression. Clinically, birds with chronic aspergillosis are thin (especially breast muscle), and are often reluctant to fly or are incapable of sustained flight."
The Web page continues: "The acute form of the disease is triggered by inhalation exposure to massive numbers of spores.... Acute aspergillosis directly affects the lungs and is characterized by the development of small (1-3 mm diameter), yellow-white nodules throughout the lungs. The disease progresses rapidly over a period of several days and the birds typically die without noticeable weight loss. People who feed birds have been traditionally warned about feeding birds moldy birdseed or bakery products."