Endangered Key deer in fight for survival against screwworms
The planet’s last remaining herd of tiny Key deer is getting a clean bill of health just in time for spring fawning season.
A grisly outbreak of flesh-eating New World screwworm, that killed 135 deer — or roughly an eighth of the herd — appears to have been stamped out. On Wednesday, U.S. Fish and Wildlife officials announced that no new flies have been detected over the last 90 days in the Lower Keys, where the outbreak erupted late last summer. The agency stopped giving deer anti-parasitic drugs to the deer on Monday and plans on ending the release of sterile flies on April 25.
“What was most impressive was not just the level of passion and commitment that people demonstrated for the Key deer, but the way so many agencies and interests came together to solve this crisis,” National Key Deer Refuge manager Dan Clark said in a statement.
The outbreak, the first in the continental U.S. in thirty years, triggered an all-agencies-on-deck response. The state’s top vet ordered a quarantine zone that stretched from Key Largo to Key West. The U.S. Department of Agriculture sent a team of entomologists that released millions of sterile flies across the Lower Keys. And refuge staff outfitted about 30 female deer with radio collars to keep a closer watch in case the outbreak spread across the herd of about 835 deer. Dozens of residents also formed an amateur treatment team, dosing deer and then tagging with spray paint.
135The confirmed number of Key deer deaths from screwworm
It’s still not clear how the flies arrived in the Keys, FWS spokesman Brian Hires said. They have been documented in Cuba and other Latin American counties, although the U.S. maintains a barrier with a sterile fly breeding lab in Panama.
“They’ve considered doing the pathology check, but it would be complicated,” he said.
And while releasing sterile flies is considered the standard method of dealing with an outbreak among livestock, it had never been tried before on a wild herd. The make-up of the herd also complicated the plan: many live near neighborhoods and roads, drawn by tourists and some residents feeding them, but many more live in the 8,500-acre refuge’s inaccessible back country.
Hires credited much of the success to the residents: about 140 who treated deer twice a week over the last six months.
With the fawn season set to begin any day, Hires said biologists will continue to monitor the collared females for signs of infestation. The flies are drawn to open wounds, where they lay their eggs so larvae can feed on live tissue. Data collected from the collars will also help improve management of the herd, which before the outbreak died mostly in vehicle collisions along the busy Overseas Highway.
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