There’s New Hope for Saving the U.S.’ Most Endangered Bird

Fewer than 150 Florida grasshopper sparrows remain in the wild, but scientists have bred the bird in captivity for the first time.
A Florida grasshopper sparrow watches its newly hatched chicks. (Photo: RSCF/www.rarespecies.org)
May 17, 2016· 2 MIN READ
John R. Platt covers the environment, wildlife, and technology and for TakePart, Scientific American, Audubon, and other publications.

Four tiny newborn chicks chirping away at the Rare Species Conservatory Foundation in Loxahatchee, Florida, represent a beacon of hope for one of North America’s rarest birds, the Florida grasshopper sparrow.

Fewer than 150 of these critically endangered birds live in their only habitat, the dry prairie grasslands of central Florida. Now we can add four more to the count. The new chicks are the first Florida grasshopper sparrows to ever be bred and hatched in captivity.

The chicks hatched on May 9 and 10 and are “making good progress,” said Ken Warren, a spokesperson for the United States Fish and Wildlife Service, one of several organizations working to save the species from extinction. The birds’ population has declined from an estimated 1,000 birds less than 20 years ago, mostly due to habitat loss but also possibly due to egg predation by invasive fire ants.

The new generation of Florida grasshopper sparrows almost didn’t happen. Their parents came from two nests of newborn birds discovered in 2015 by biologists who have been monitoring the species. At the time it looked as if both nests would fail. One was in a site that could have easily become flooded. The second nest had lost its mother, for unknown reasons. The two clutches, totaling six birds, were brought into the conservatory and hand-raised. Two additional juvenile birds were captured to help raise the chicks.

Last month, a few of the now-adult captive sparrows started to exhibit mating behavior. One nesting attempt failed, for unknown reasons, but the second resulted in the four eggs that hatched last week.

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Warren said the priority will be to observe the chicks to make sure they continue to do well. They will grow quickly and are expected to be fully independent within three weeks of birth. Eventually they’ll reach their full size of five inches in length.

Meanwhile, work continues on efforts to better understand and protect the few secretive birds that remain in the wild. “Each year we hire a team of highly qualified field biologists who monitor the breeding pairs and install predator deflection fences around nests to increase the probability of survival,” said Erin Ragheb, an assistant research scientist with the Florida Fish and Wildlife Conservation Commission. “This is a challenging task because the birds spend most of their time foraging on the ground and can be difficult to observe among the dense grasses. Locating and protecting their nests requires careful observation skills and a lot of patience.” That paid off when last year’s nests were discovered and saved.

Ragheb’s work focuses on identifying the sparrow’s life stages. Last year she coauthored a paper that examined the songs male Florida grasshopper sparrows use to attract potential mates. She also focuses on “providing recommendations to land managers on how to create or preserve habitat that is most suitable for the birds,” a necessary task, because what little remains of the sparrow’s natural habitat is split between state and federal land and privately held cattle pastures.

As for the new chicks, they’ll probably spend the rest of their lives at the conservatory. “Right now there is no plan to release them back into the wild,” Warren said. “The probability is that they will remain in captivity and be kind of foundational to a colony we hope to establish.” If enough birds are born in captivity, some may be released back into the wild, he said. “This is the first step.”