Fearing that the Florida grasshopper sparrow might go extinct in as little as two years, wildlife advocates have begun pressing federal officials to approve an emergency effort to capture some of the birds and breed them in captivity.
The Central Florida bird is a subspecies of the grasshopper sparrow found only in vast, treeless prairies south of the Orlando area, including the Three Lakes Wildlife Management Area in Osceola County, where the largest group of the sparrows clings to survival.
Biologists have not been able to determine what's causing the subspecies' rapid decline, but they suspect a long-term factor is loss of habitat and that a more recent threat might be invading fire ants that devastate the birds' nests.
"We consider this the most endangered bird in the continental United States," warns a letter sent last week to the U.S. Fish and Wildlife Service by Audubon of Florida; Archbold Biological Station; and a University of Central Florida ecologist, Reed Noss.
"In light of population levels possibly below 200 individuals and very rapid recent declines of [the sparrow], ? we conclude that the risk of delay exceeds the risk of mistakes," the letter states.
U.S. Fish and Wildlife Service officials said steps have already been taken to evaluate whether breeding birds in captivity is needed to save the bird from vanishing.
A decision whether to pursue that option might not come soon, though the federal officials said they are aware that next spring's nesting season might be their last chance to start a captive-breeding program like the one in the late 1980s that saved the California condor from extinction.
"The clock is ticking with this species because their decline has been so dramatic over the past few years, and the populations that remain are fairly small, and each of those populations is in a declining trend," said Larry Williams, field supervisor for the agency's South Florida Ecological Services office in Vero Beach.
"But there's a lot of different factors that we have to consider, and the most challenging one is the fundamental question of whether we would do more harm than good if we go out and take sparrows or eggs out of the wild," Williams said.
The overriding concern, Williams said, is that capturing birds could further weaken the subspecies' chances of survival in the wild, especially if such an attempt to raise and expand a population in captivity were to fail.
The bird is small, elusive and hard to study. One of the things it is well known for is being closely related to the dusky seaside sparrow of east Central Florida. That bird suffered a sharp decline in numbers because of mosquito-control projects decades ago that wrecked the ecological health of the marshes where it lived.
A last-minute effort in 1979 to capture the few remaining birds for breeding failed because only males could be found.
"We have talked with a lot of people that worked on dusky seasides in their last years, and the message that everybody had was, 'Don't start too late with captive breeding,'?" Williams said.
But before deciding whether to capture Florida grasshopper sparrows, researchers would like some assurance that the birds can be bred and reared in cages, then released in a manner that ensures their survival, said Mary Peterson, a Fish and Wildlife Service endangered-species specialist in Vero Beach.
Peterson said a researcher at the University of Maryland is currently raising eight to 10 Eastern grasshopper sparrows as a way to develop methods for handling and caring for Florida grasshopper sparrows in captivity.
A preliminary plan for raising the Florida subspecies in cages calls for taking in a few birds each year ? either as youngsters or eggs ? and gradually expanding the captive population to at least a hundred birds.
"One of our main concerns is having enough genetic diversity within the birds brought into captivity," Williams said.
Florida grasshopper sparrows could once choose among more than a million acres of treeless prairie for nesting places. But more than 90 percent of that habitat has been degraded by development or agriculture, according to the Florida Grasshopper Sparrow Working Group, a panel of state and federal land managers, biologists and environmental advocates formed in 2002.
Another organization pressing for captive breeding is the Everglades Coalition, which represents dozens of environmental groups.
The coalition recently issued a resolution that calls on the Fish and Wildlife Service "to proceed with alacrity in permitting and initiating a captive-breeding program."
The resolution notes that surveys last year of the three remaining refuges for the sparrow found only one of the birds at Avon Park Air Force Range in Polk and Highlands counties; 14 at Kissimmee Prairie Preserve State Park in Highlands County; and 60 at Three Lakes Wildlife Management Area in Osceola County.
"It takes a lot of people a long time to gather any meaningful information about the bird, and we may not have enough time to figure out what's wrong the birds until they are functionally gone," said Paul Gray, an Audubon of Florida biologist.
"We can get some birds in captivity and have a backup supply of the birds ? and that's a terrible way to talk about such a precious thing, but ? have a backup supply while we figure out what's wrong with the birds in the wild," Gray said.
kspear@tribune.com or 407-420-5062
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