By Anders Gyllenhaal
When researchers built a giant grid of radio receivers for tracking birds in the sandy fields south of Orlando, they hoped to find new ways of protecting the struggling Florida Scrub-Jay.
They discovered something else along the way. Birds are a lot more like people than either species might have thought.
The grid concept is something new in bird research. By setting up receivers throughout the Scrub-Jay’s territory, and then equipping the birds with solar-powered tracking devices, biologists can follow the birds’ every move all day long for months at a time.
The research is still in its early stages, but some intriguing behaviors have jumped out:
Like teenagers everywhere, the young jays form tight cliques of favorite friends. Like many parents, adult jays try to build enough territory to pass sections along to their offspring. When the birds start looking for mates, they come up with ways of sizing up the competition – and sometimes coming between couples.
“It turns out that they have very complicated social lives that aren’t that different from ourselves,’’ said Reed Bowman, a research biologist at the Archbold Biological Center that has been studying the Florida jays for decades.
The Florida Scrub-Jay is one of the state’s most popular birds and an uncommon segment of the jay species. They’re found only in Florida – and now only in a few central Florida counties. They’re unusually friendly toward humans. Proponents have pushed, so far without success, to make the Scrub-Jay the state bird in place of the more ordinary Mockingbird.
But they’ve been in a long, steady decline, mostly because the jays are so dependent on dry, elevated and mostly treeless habitat that has steadily been lost to development. Wildlife managers are trying to learn how to protect the last 4,000 Florida Scrub-Jays.
The Archbold researchers believe the key is understanding how the birds use what’s left of their habitat. They want to know how the young birds approach breeding and what wildlife managers can do to create the best environment.
At first, researchers thought they could conduct this research by simply watching the jays in the field. “But you could only track a handful of birds at a time,’’ said Young Ha Suh, a doctoral candidate at the Cornell Lab of Ornithology and the project’s lead researcher. “It was really time-consuming.’’
So the Archbold team looked for different ways of tracking the jays. They came across a new technique created by a small New Jersey company called Cellular Tracking Technologies (CTT) that has developed data-driven approaches over the last decade.
Bowman, Suh, CTT and their crew put digital receivers on top of poles every 200 meters through the elevated ridge that runs through the center of the state. It’s one of the best remaining tracts for this species and today is home to 200 or so.
They gradually captured young jays by luring them into cages with the peanuts they love. Then they slipped on solar-powered tracking devices that weigh less than a gram.
Signals from the jays are sent to the receivers, then up to a huge antenna on a nearby water tower. From there, they go to a computer set up to collect the huge amount of data from dozens of jays, flying around their territory all day long.
The first configuration of the grid was partly meant to test out the technology. But the data that flowed in quickly started painting pictures at odds with some of the presumptions about the bird.
One of the big questions was why young Scrub-Jays stay with their parents to help raise siblings after they’ve reached breeding age. And what do they do during that time when most other species have already started breeding?
“They form cliques, for lack of a better word,’’ said Bowman. “Then they go out, and they tend to associate with the same birds over and over.’’
Just like human teenagers, the birds pay close attention to who they hang out with. Some choose jays with similar personalities in terms of how active, aggressive and risky they are. Others go with opposites.
“If they mix these personalities, they could sort of complement each other,’’ said Suh.
The jays are a patriarchal society, with only males given portions of their parents’ territory to call their own. Females have to go far afield in search of mating prospects. Suh says they don’t mind moving in on the territories of other females.
“They have to look around for potential opportunities,’’ she said. “If there’s a territory where the female breeder is old or sick, and they see that the female might die soon, they’ll think: ‘Maybe I could come visit this territory more often.’ ’’
The young birds do a great deal of exploring in these groups before settling down to breed. By analyzing their travels, biologists are learning what kinds of habitat are best for the birds, how much land they need and what might be the best way for managers to care for that land.
The project is moving into a second phase that will greatly expand the territory under study, increase the receivers and the number of birds they track and dig into their behavior more closely in the coming year.
There’s a lot at stake.
Despite years of study and conservation efforts, the Scrub-Jays remain a diminishing species. Now researchers are worried that as sea level rises, development pressure will mount on what’s left of the elevated land for the birds.
That means they want to understand such management tools as how often to conduct controlled burns, how to manage the undergrowth with the birds in mind and how to help protect the jays from predators.
The project is also helping to advance a new approach that’s part of a boom in research technology reshaping traditional field study. David La Puma, director of global markets development at Cellular Tracking Technologies, said the data provides a view of behavior you can’t otherwise get.
“It’s fascinating to be able to map these birds remotely; to really learn and understand what they’re doing. That’s something that was always done through direct observation, which is logistically quite challenging,’’ he said. “We’ve really only scratched the surface thus far, so we’re all very interested to see what the Archbold team discovers in the coming months and years. This work is truly groundbreaking.’’
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