Central Florida endangered sparrow 'unlikely' to survive in the wild

A Central Florida bird has begun to plunge so swiftly toward extinction in the wild that biologists are considering the risky option of capturing the last of the species, including fewer than two dozen females.

If that happens, those Florida grasshopper sparrows would be added to a pair of small, captive populations. But there are rising fears the captive birds are being threatened by lethal disease as they are being bred for what biologists hope will be their eventual release.

"We are at a moment of reckoning," Audubon biologist Paul Gray said.

State, federal and environmental groups have struggled for much of the decade to revive the bird, spending more than $1 million on research, , predator deterrence and restoration of landscapes. But they have not conclusively determined what's causing its rapid demise.

Small, brown and sometimes singing a grasshopperlike buzz, the sparrow is unknown to city or suburban dwellers as it inhabits remote, treeless prairies of Osceola County and farther south. It is often referred to as the most endangered bird in the continental U.S.

Last year, biologists counted 40 females and 74 males in the wild. They were disheartened this year after finding 22 females and 53 males.

Officials at the U.S. Fish and Wildlife Service say that despite intensifying efforts for their recovery, Florida grasshopper sparrows are on a path to vanish from their native landscape in as few as two years.

"We are trying to set expectations, which for us (is) the likelihood of a wild, sustaining population is low," said Larry Williams, the agency's supervisor for ecological services in Florida.

Ashleigh Blackford, a supervisory biologist with the , said assaults on the sparrow that include loss of habitat, predators, fire ants, storms and disease may be beginning to "snowball."

"We want to be transparent with the public that we are getting very close at this point," Blackford said of possible extinction in the wild.

Biologists are haunted by the last bird that vanished in the continental U.S., the dusky seaside of Orange and Brevard counties.

The last, five of those sparrows were captured in 1979 from marsh in east Orange. They were to be the core of a population bred in captivity, but all were males and died out in 1985.

Last year, the Rare Species Conservatory Foundation in Palm Beach County began to hatch Florida grasshopper sparrows for the first time in captivity.

Foundation director Paul Reillo said captive breeding, while promising initially, has been challenged by the emergence of at least one deadly disease that involves parasites invading their guts.

As laboratory work proceeds toward identifying pathogens and possible remedies, Reillo thinks the Fish and Wildlife Service must move quickly.

"The only option for preventing extinction and for recovery is to bring all the birds into captivity," Reillo said. "If you leave it on the landscape, it will go extinct. If you don't bring it in, you're losing genetic diversity that would give you hope for the future. There are no guarantees but it's the only shot that we've got."

But another is worried that capturing the remaining sparrows would erase their knowledge for behaving and surviving in nature.

"There are advantages to leaving some birds in the wild," said Andrew Schumann, a collections manager at White Oak wildlife conservation center. "When we do reintroductions, there would be wild birds there to show them the ropes."

His North Florida center began to hatch Florida grasshopper sparrows this year.

Schumann said that despite the difficulties of raising birds in captivity, including disease and sparse knowledge about diets and habits, he thinks breeding efforts will improve and accelerate.

"How they use the landscape and what they feed on—that original role they played in the ecosystem may not be preserved if you catch all those wild birds," Schumann said. "I'd like to see birds released immediately because I do not want to lose all the birds in the wild."

Audubon's Gray was an early proponent of bringing some into captivity for breeding.

"If we wanted to bring all of them in, that would be a monumental decision," Gray said. "Our position is, let's get everybody in the room to talk about it."

Several involved expect to meet for critical decisions as early as January.

The U.S. Fish and Wildlife Service is urging donations to the Fish & Wildlife Foundation of Florida, which has created a recovery fund for Florida grasshopper sparrows.

©2017 The Orlando Sentinel (Orlando, Fla.)
Distributed by Tribune Content Agency, LLC.

Citation: Central Florida endangered sparrow 'unlikely' to survive in the wild (2017, December 27) retrieved 4 December 2022 from https://phys.org/news/2017-12-central-florida-endangered-sparrow-survive.html
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