The Most Endangered Bird in the Continental U.S.
Our male had flown into a mist net we’d set up in his territory. Grasshopper sparrows got their name because the male’s faint, high-pitched vocalization sounds like the buzz of a grasshopper. This may be an adaptation to delude predators and still allow territorial defense. Miller and Sneckenberger have young ears, so they had been able to hear 160184057 singing. Audubon Florida biologist Paul Gray and I, standing beside them, could not.
Miller had crouched behind the net, playing the song from an app on his iPhone. The bird had veered away half a dozen times, an indication that he was “net savvy.” The band on his left leg confirmed this. The number, 160184057, revealed that in 2007 he’d been caught in the park by Reed Noss and his team from the University of Central Florida.
The Florida Grasshopper Sparrow Working Group (on which Miller, Sneckenberger, Noss, and Gray serve) fears that the population is increasingly dominated by aging males. Females may be more vulnerable to predation because they incubate eggs and brood young on the ground. And the birds are almost certainly suffering an “Allee effect”; basically, so few remain that they have trouble finding mates, suffer inbreeding, and lose the ability to cooperate in social behaviors such as combined vigilance against predators. Disease and fire ants may be depressing the population further.
Fire ants and nesting Florida grasshopper sparrows like the same habitat—the wetter, treeless parts of the prairie. In the area defended by 160184057, Miller has found broods killed by fire ants. The areas of the park shaded by saw palmettos support few ants, and ground nesters that like this habitat, such as meadowlarks and Bachman’s sparrows, are doing fine.
Noss believes the wet sections preferred by the sparrows (perhaps because they produce more insects and grasses) may have become “ecological traps.” Not only are they seething with fire ants, they’re subject to flooding. “We found the highest success in the park’s drier parts even though fewer birds nested there,” he says.
Before I released 160184057, he’d hopped and preened in a wire-framed box lined with black velvet while Joel Sartore recorded him in video and still frame. Four strobe lights, powered by a gasoline generator 150 feet away, flashed in radio-controlled synchrony with the camera shutter.
Some 20 years after earth lost its last dusky seaside sparrow, Sartore photographed the preserved carcass for National Geographic. I asked him what he’d felt. “It was a pilgrimage for me,” he said. “I was sad and awed at the same time. I held him in my hand, and turned him over a few times. He didn’t look anything like he looked in life. Dead birds fade.”
Seven years ago, with funding from National Geographic, Sartore started the Photo Ark Project, an effort to get people to care that we are in the process of dooming half the planet’s species to extinction in the next 100 years. “I want a record of what will be gone,” he told me. “And maybe if I can get people to fall in love with animals like the Florida grasshopper sparrow, we can save a few. It’s folly to think that we can keep killing off species and get away with it. If we drive enough to extinction, we’ll go extinct, too.” So far he has photographed 2,600 species for the project, all without injury or incident.
As recently as 2010 members of the Florida Grasshopper Sparrow Working Group were talking about captive breeding as a last-ditch possibility. Now they’ve sold it to the Fish and Wildlife Service as the best remaining option. Captive breeding is a bit like throwing antique china out the attic window during a house fire and hoping a few pieces land intact. But occasionally, as with California condors and black-footed ferrets, it works. If the feds had listened to the large element of the environmental community (me included) that opposed evacuation of these species from the wild, both would now be extinct.
On November 6, 2012, Audubon Florida and allies urged the Fish and Wildlife Service to remove eggs or chicks in the spring of 2013. “We consider this the most endangered bird in the continental United Statesand worthy of extra efforts,” they wrote.
After some hesitation, the service approved captive breeding in January 2013.
The service has learned from its failure with the dusky seaside sparrow. Like the Florida grasshopper sparrow, the dusky didn’t migrate. The sex ratio of the dusky (and very likely the Florida grasshopper sparrow) became skewed in favor of males. The downward trajectories of both are identical and caused by the same kind of habitat destruction, and both apparently suffered from Allee effects.