Wednesday, June 05, 2013

The Dusky Seaside Sparrow; Anniversary of Extinction

It will soon be June 17, a sad anniversary in conservation. It was on that day in 1987 that the last dusky seaside sparrow died. If God truly sees the sparrow fall, then that day must have broken His heart.
Several American birds have come to an ignominious end, with the last known specimen dying alone in a zoo.  Thiw was the fate of the passenger pigeon and then of the Carolina parakeet, which officially passed away in the Cincinnati Zoo in 1914 and 1918 respectively. (There were several sightings of each species and one finding of parakeet eggs after the official extinction dates, but the birds didn't survive much longer if at all.)
The dusky seaside sparrow died out in something of the same manner. A victim of development and mosquito control efforts that eliminated its habitat on Florida's east coast, the dusky's struggle for survival was carried on in the shadow of the ultimate symbol of progress, the gantries of Kennedy Space Center.
The bird's numbers had been dwindling for a long time before a wildlife refuge was established in 1971.
Even then, fires and pesticide use continued to shrink the population, and every year brought fewer sightings.
Ornithologist Herb Kale felt the bird's fate was sealed when, in 1973, it was reclassified from a species to a subspecies. Much more effort is likely to be spent on an animal if it's considered a species, and therefore unique. In addition, bird watchers, an important constituency, lose interest, because subspecies don't count on a birder's "life list." That this reclassification has since been proven correct doesn't change much.

Painting by John James Audubon

In 1979, in a last effort to save the dusky, ornithologists captured five of the six birds they could find. All, including the one who eluded capture, were males. With no dusky females, the rescue team tried to preserve the bird's genes by crossbreeding the males with their closest relative, the Scott's seaside sparrow. This happened in a facility provided by a symbol of development, Walt Disney World, in a gesture mixing altruism and public relations. (Disney at some point proposed the dusky⌐Scott's hybrids be designated a new subspecies called Ammospiza maritimus disnei.)
The last known dusky seaside sparrow, "Orange" (named for his leg band), died on June 17, 1987. Two years later, a storm damaged the roof of the research compound, and the four living dusky⌐Scott's hybrids died or escaped. That was Disney’s version, at least. Author Mark Walters, in his book A Shadow and a Song, wrote that rats actually got into the cage and killed at least two birds. One or two sparrows escaped or were released, and Disney told the storm story to keep from appearing negligent.
If this little bird is genuinely extinct (and the IUCN classified it in 1990), then the moment of its passing is known with saddening precision.

Avise, John C., and William S. Nelson. 1989. "Molecular Genetic Relationships of the Extinct Dusky Seaside Sparrow," Science, February 3. Bergman, Charles. 1990. Wild Echoes. New York: McGraw-Hill. \Cadieux, Charles L. 1991. Wildlife Extinction. Washington, D.C.: Stonewall Press.
Walters, Mark J. 1992. A Shadow and a Song. Post Mills, VT: Chelsea Green Publishing Co.
"Dusky Seaside sparrow (Ammodramus maritimus nigrescens)," U.S. Fish and Wildlife Service,  no date. For Joel Sartore’s image of the last dusky, see this link.

No comments: