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Grasshopper Sparrows Live in Area Grasslands
In a feel-good success story about the rebound of one local native species, the Florida Fish and Wildlife Conservation Commission and partners have released their 1,000th captive-bred Florida Grasshopper Sparrow.
Grasshopper Sparrow thrive on the fire-dependent habitat of open grasslands found across central Florida. Fire management is a critical tool to ensure the survival of these and many other species.
Florida Grasshopper Sparrows live only in central Florida's grasslands and are federally designated endangered. To preserve the species, the allied teams began a captive breeding program in 2015.
According to Adrienne Fitzwilliam, assistant research scientist at the FWC's Fish and Wildlife Research Institute, the Florida Grasshopper Sparrow is a non-migratory subspecies of the Grasshopper Sparrow.
"Like other grassland birds, they have experienced significant declines due to habitat loss and habitat management challenges," Fitzwilliam told Kite Tales, the FWC's newsletter. "The dry, open prairies where they live once burned frequently from lightning strikes but are now unlikely to burn naturally due to habitat fragmentation."
The following interview is reproduced from Fitzwilliam's interview with Kite Tales.
"Maintaining the prairies and open grasslands requires active habitat management, particularly prescribed fire. The Florida Grasshopper Sparrow is a small bird and might seem like an unlikely champion, but the specific research we've been doing on the species has led to improvements in habitat management, such as adjusting burn intervals and controlling encroaching trees. This has been good for all the prairie birds, especially other ground nesters like Bachman Sparrows that benefit from a regular fire regime. Furthermore, land acquisitions for the conservation of the Florida Grasshopper Sparrow also support other species that share its habitat.
Left: Florida Grasshopper Sparrow carrying an insect. Right: Florida Grasshopper Sparrow nestlings.
What's the typical day in the life of a Florida Grasshopper Sparrow?
They are very funny birds. They prefer to spend a lot of time on the ground, which is why they need constant fire and disturbance in their habitat. They like grass that creates small tunnels, and they need bare ground for navigation. They feed on grasshoppers, which is how they get their name, but they also eat seeds, especially after the breeding season when insects are less available and they're not feeding nestlings. They are a short-lived species with an average lifespan of about three to four years, meaning birds born in one breeding season are ready to breed the very next year. Life on the prairie is dangerous, especially for the female Florida Grasshopper Sparrow, who spends most of her time on the nest. Corn snakes are a common predator, often consuming the female along with her eggs or nestlings.
When did the captive breeding program start?
According to Fitzwilliam, populations crashed in the early 2000s. At that time, no one had attempted captive breeding with this species or any sparrow with a similar life history, so we lacked a model program. We were hesitant to remove Florida Grasshopper Sparrows from the wild without being reasonably sure they would breed in captivity. To test the possibility, we first reared Eastern Grasshopper Sparrows, a migratory subspecies, to see if they could survive and breed in an enclosure. When that was successful, we started breeding Florida Grasshopper Sparrows in 2015. Our main facility at the time was White Oak Conservation. They have amazing outdoor cages that mimic the prairie habitat and even burn inside the cages in the offseason to maintain suitable conditions.
Kite Tales is a publication of the Florida Fish and Wildlife Commission sharing news of our threatened and endangered species and habitats across Florida.
We also had to determine whether to release hatch-year birds or wait until the following breeding season after their first winter, when mortality is high for young birds due to inexperience. An experiment showed that hatch-year birds ultimately had better recruitment and survival rates than second-year birds, who imprinted on their enclosure environment.
The conservation breeding program is amazing, but it's only part of the overall effort. The field crew works incredibly hard to find the nests, band nestlings and protect the nests with fences. If flooding is predicted, they even lift the nests. A tremendous amount of work goes into ensuring that the Florida Grasshopper Sparrow has the best chance of recovery.
Where are the birds released?
There are multiple release sites. We have a permanent aviary at Three Lakes Wildlife Management Area and multiple mobile aviaries at Avon Park Air Force Range, where we celebrated our 1,000th release. Imagine a trailer with a cage built on top, filled with sand and plants from the prairie. The birds spend one night in the aviary before release, with enough food and water to last until morning. Then, we remove the doors and let them walk out onto the prairie.
Inside a Florida Grasshopper Sparrow mobile aviary. Photo by Rachael Schirmer.
When we started releasing birds at Three Lakes WMA, we knew the new birds would be attracted to the singing of the resident Florida Grasshopper Sparrows. Avon Park was added as a second release site in 2021, and they had nearly no resident Florida Grasshopper Sparrows. We were eager to see if the released birds would stay at Avon Park at the same rate as at Three Lakes WMA, and they did! This is excellent news because it means that even if the birds are initially absent from a site, we can successfully reintroduce them if the habitat is suitable and there is historical evidence of their presence.
Young birds are transported inside a Florida Grasshopper Sparrow mobile aviary before their release. The juvenile birds have been shown to rapidly adapt to their new habitats after release.
How many birds are typically released at a time?
It depends on how many are born during a period. Our three conservation breeding sites-White Oak Conservation, Brevard Zoo, and Avian Preservation and Education Conservancy-keep the chicks with their parents until they are 28 to 30 days old before separating them. At this stage they are not yet independent enough to be released. Birds of similar age are grouped together and may be moved to Welaka National Fish Hatchery to await release. When they reach 40 days old, they are transported as a group to the release site. We've released groups as large as 25 birds, but never just one bird. They are always released in groups to mimic their natural behavior. Once released, juveniles often group with other Florida Grasshopper Sparrows and sometimes with juvenile Bachman's Sparrows.
What was the 1,000th release like?
We were really excited. We tried to prepare everyone for what it would look like, as it's not as dramatic as releasing a panther or an eagle. During the very first release, we didn't even see the birds come out; they just walked out quietly, like little mice. While we tried to temper everyone's excitement, there was one particularly active bird that flew around the aviary before finally flying out. It was a wonderful collective experience for everyone on the project and at Avon Park to see that bird find its new home.
This project was funded in part by a grant from the nonprofit Fish & Wildlife Foundation of Florida via proceeds from the "Conserve Wildlife" license plate. Since its founding, the Foundation has raised and given away more than $55 million for conservation, outdoor recreation, youth programs and camps. For more information, please visit WildlifeFlorida.org.
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