The wildlife managers who bred more than 200 Florida Grasshopper Sparrows in a laboratory setting over the past two years knew they faced a tricky question when it came to releasing the birds into the wild this spring:
Would they know how to act like grasshopper sparrows?
Could they sing the sparrow’s unique courting song? Would they know how to hide from hawks? Would they have the instincts to build nests, mate with wild sparrows and raise their young together?
The captive-breeding experiment is the culmination of a decades-long project to revive the most endangered species in the U.S.. Only 30 pairs of the sparrows remained in the wild when the team decided they had no choice but to try producing chicks in captivity, then introducing them back into the wild in hopes they’d multiply.
The answers to all their questions came pouring in over the course of the breeding season that is now coming to a close.
The birds not only mastered the routines of the mating season, they gave birth to a new generation of Florida Grasshopper Sparrows over the summer. ( Forty-two birds were born from captive-bred birds and altogether 64 were born from wild and captive-bred birds.) Almost all have now left the nest and flown off to begin life on their own.
“We’re very happy with what we saw this first season,’’ said Juan Oteyza, the research biologist with the Florida Fish and Wildlife Institute that oversees the project. “It seems to be paying off.’’
Craig Faulhaber, avian conservation coordinator for the state Fish and Wildlife Conservation Commission, said it was hard to tell the captive-bred from the wild sparrows. “They showed all the normal behaviors,” he said. “They bred successfully. They took care of their young. They acted just like wild sparrows.”
Flying Lesson: The project to save the Florida Grasshopper Sparrow has been full of discoveries for researchers. They’ve learned what it takes to breed birds in captivity, protect fragile nests from harm and how to begin to replenished the depleted population. It’s not yet clear if the project will be successful, but already the lessons are proving valuable to help understand the woes of the grassland birds like the sparrow.
The grasslands 50 miles south of Orlando where the last of the grasshopper sparrows have congregated is one of the most studied patches of bird habitat in the country.
State and federal managers, nonprofit supporters and some of the nation’s leading bird researchers spent hours walking the fields and peering through binoculars at the sparrows on their daily rounds. Every sparrow is known, identified by a combination of colored bands on its legs.
We’ve been following this story for more than a year, as it is one of the innovations scientists are trying in order to save fragile species. Here’s an in-depth package that ran in the Washington Post in May, and here’s a Flying Lessons post on the long term outlook for species like this.
The rescue mission is important for a litany of reasons.
The Florida Grasshopper Sparrow is the flagship bird of the unique grasslands called the Florida Prairie, 90 percent of which ha disappeared territory as the state has grown. And while the prairie environment is distinct, the troubles with grassland birds are not; no other segment of birds has faced declines that grassland species have across the country. What researchers learn from the grasshopper sparrows can help other birds.
The encouraging report from the breeding season is some of the first good news for the grasshopper sparrow since its sudden and mysterious decline that began nearly two decades ago. Despite the progress on the sparrow population, researchers still don’t know what is causing the near evaporation of the subspecies.
Reed Bowman, director of Archbold Biological Station’s Avian Ecology Program who has worked on the project since its inception, said the arrival of so many captive-bred birds could help researchers decipher the cause of the declines. Wild birds have continued to decline right up until this breeding season; if the captive population proves to be healthier, that would indicate a biological cause of the decline, such as inbreeding, as opposed to an environmental one.
“Honestly, that would be great news if (captive-bred birds) declined at a lower rate than wild birds,” he said. “We will get some insights.”
The breeding results are a reminder of how challenging this rescue mission will be.
Most of the released birds did not survive, which is normal for birds like these. Others didn’t end up breeding the first year out, although they may in later years. So while the total population of grasshopper sparrows on these grasslands about doubled, the total number of breeding pairs — the key calculation for expanding the population — remained about the same for the sparrows at the several site in the area where they’re found.
Still, the species is making progress, which in turn is encouraging to the consortium of state and federal agencies, conservation organizations, non-profits and foundations that help fund the project that costs about $1.2 million a year. “This has been a huge positive,” said Bowman. Andrew Walker, president of the Fish and Wildlife Foundation of Florida, a nonprofit organization that helps raise funds for the project, added: “We’re committed to this for the long haul.”
Understanding the inner workings of birds