Saturday, August 4, 2012

What is happening to Florida’s grasshopper sparrow? Published on Saturday August 04, 2012 Kevin Spear The Orlando Sentinel KENANSVILLE, FLA.—A type of sparrow that lives only in Florida has mysteriously plunged in number so dramatically that scientists fear it will vanish well before the end of this decade. Florida grasshopper sparrows, which inhabit grasslands in the state’s interior south of Orlando, have been listed as endangered for 26 years. But the furtive birds have all but disappeared in recent years from one of their last three prairie refuges and, in what has become a wildlife emergency, may now total fewer than 200 in just two counties. The sparrows’ extinction would likely be the nation’s first loss of a bird since the late 1980s, according to the Cornell Lab of Ornithology. That’s when the dusky seaside sparrow, also a Florida native, slipped out of existence. The threat of losing another bird unique to Florida alarms scientists. “This seems to be the most highly imperiled bird in all of mainland North America,” said Reed Noss, a biology professor at the University of Central Florida. “At the present rate of decline, it’s going to be extinct in as few as three years and, unbelievably, we don’t know why.” The small bird is firmly adapted to “dry prairie.” Florida had more than 1.2 million acres of that treeless terrain, but 90 per cent was turned into inhospitable cattle pasture by the end of the 20th century. The bit that remains is one the state’s last old-growth landscapes, an ecosystem carpeted with an astounding variety of grasses and flowering plants. Scientists have no doubt that the loss of habitat caused most of the bird’s decline. As for what’s behind the recent population dive, they surmise invading fire ants are eating chicks and increasingly variable weather is flooding more nests. They also suspect disease and loss of genetic diversity. The various factors could also be acting together in what scientists call an “extinction vortex.” The bird eats grasshoppers and sings like one, with a “tick, tick, buzz.” It also tends to run — hidden by dry-prairie grasses — bedevilling researchers’ attempts to study it. What might be the bird’s most serious threat now, researchers fear, is indifference to its plight. Florida grasshopper sparrows do not visit backyard feeders, nor do they elicit the popular affection shown for the likes of West Indian manatees and Florida panthers. But officials at the U.S. Fish and Wildlife Service, saying they are treating it as an emergency, have raided their tight budget to fund accelerated studies, push for restoration of dry prairie, and took the unusual step of assigning a biologist to focus full time on the bird.