Racing to Save the Florida Grasshopper Sparrow

From the Spring 2017 issue of Living Bird magazine. Subscribe now.

The Bird

The Florida Grasshopper Sparrow is one of America’s most imperiled birds. A sparrow subspecies found only in Florida’s dry prairie, it was listed as federally endangered in 1986 after a population decline of about 90 percent. Even with federal protections, the sparrow’s alarming decline continues today. Biologists from government agencies and conservation groups are conducting urgent field research to understand and combat the causes of decline and save this bird from extinction.

The Setting

The Florida Grasshopper Sparrow is native to Florida dry prairie, a flat, treeless grassland interspersed with palmetto islands and dwarf oaks. Despite being called dry, this prairie often floods during the wet season from May to October. More than 20 bird species rely on habitat in and near the dry prairie, including Burrowing Owls, Sandhill Cranes, and Eastern Meadowlarks.

Florida dry prairie is within the headwaters of the Everglades, a mosaic of cypress swamps, pine forests, upland oak scrub, and grasslands. Less than 5 percent of the Florida dry prairie—the Florida Grasshopper Sparrow’s vital habitat—is left. The sparrows survive in only a few remnant populations in Florida.

The Decline

During the 20th century Florida saw the extinction of the Ivory-billed Woodpecker, Carolina Parakeet, and Dusky Seaside Sparrow. A last-ditch conservation effort tried to save Dusky Seaside Sparrows in the 1970s. Captive breeding efforts were tried, but the bird still disappeared into extinction in 1987, a victim of habitat loss. The Dusky’s long shadow looms over current efforts to save the Florida Grasshopper Sparrow. Have scientists and conservationists learned enough in the last 30 years to save another imperiled Florida sparrow? Will society put that knowledge into action to save the bird?

Reasons for the decline include land uses as varied as cattle ranching, citrus growing, and clearing for housing developments, as well as predation by spotted skunks and—incredibly—the tiny, invasive fire ant.

In the late 1800s, large-scale land drainage for agriculture and development began in the northern Everglades. Much of what was once dry prairie is now pastures for cattle. Today, cattle ranchers play an important role in conservation by keeping land in grass rather than converting pastures into housing developments. But in the past dry prairie was drained and planted with exotic vegetation such as South American bahiagrass to create cattle pastures. These prairie-to-pasture conversions degraded the habitat quality of dry prairie.

And just in the last 75 years, Florida’s human population has dramatically increased from around 2 million to more than 20 million residents. Continued land development has fragmented the remaining dry prairie, which now exists in isolated habitat islands of conservation lands. Meanwhile, housing developments continue to expand and put pressure on Florida’s wildlands.

Citrus groves are almost synonymous with central Florida and the northern Everglades. Twice a year orange blossoms perfume the air of the region, but citrus has sometimes come at the expense of Florida’s birdlife. Many groves were planted on converted dry prairie that was likely home to Florida Grasshopper Sparrows in the past.

Solutions

Habitat rehabilitation and management is critical if the Florida Grasshopper Sparrow is going to maintain a wild population. The entire population of wild Florida Grasshopper Sparrows is down to fewer than 150 birds. These last survivors of their species are closely monitored, and biologists use a number of approaches to ameliorate threats:

• Population monitoring: Using mist nets, biologists catch adults to check their health and use bands to track their survival.
• Nest protection: Biologists put up barriers to exclude predators and even rescue chicks from drowning in heavy rainstorms.
• Blood samples taken from adult Florida Grasshopper Sparrows tell researchers about the genetic and physiological health of the birds. So far, they have found no evidence of inbreeding, which can be a problem among small populations of endangered species.
• Prescribed fire removes trees that have encroached on the dry prairie and promotes the growth of native plants. It is a management tool used to mimic lightning-caused wildfires that were once common in Florida and played an important role in maintaining ecosystems.
• Captive breeding: After several years of consideration, and under the shadow of the Dusky Seaside Sparrow extinction (above), six Florida Grasshopper Sparrow chicks were taken from the wild in 2015 and brought to the Rare Species Conservatory in Loxahatchee. In 2016, additional eggs and nestlings were brought to the Rare Species Conservatory as well as the White Oak Conservation Center in Yulee.

The Future

Will the Florida Grasshopper Sparrow make it through the 21st century? Or even the next decade? Prospects seem bleak, but there is reason for hope. More than 75 dedicated wildlife biologists in a working group have pledged not to give up. They continue to adapt and move forward with recovery plans. They cannot turn back the clock on the past 100 years of landscape changes, but through their persistence they seek to show that Florida can still make room for one of its smallest, most vulnerable birds.