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The Inquisitive Florida Scrub Jay
April 1, 2014

[image-36]By Anna Heiney
NASA's Kennedy Space Center, Fla.

[image-51]If you walk into Florida's sandy pine flatwoods, you probably won't see them right away.

But they'll see you. As you move among the saw palmettos and scrub oaks, they'll watch your every move to see if you're a threat.

It won't take long, though, for the Florida scrub jay's natural curiosity to kick in -- and one or more of the blue-and-gray birds might come a little closer to get a good look at you.

"This is a bird that is very intelligent, very social, and tends to be very curious about humans," said David Breininger, a wildlife ecologist with InoMedic Health Applications (IHA) at NASA's Kennedy Space Center in Florida, home to one of three remaining large scrub jay populations.

The Florida scrub jay (Aphelocoma coerulescens) is endemic to the Sunshine State; you won't find one anywhere else in the world. It's similar to a blue jay in color and size, but there are some physical differences, such as the lack of a crest on the back of the scrub jay's head. But there is one social/behavioral characteristic that sets this bird apart from most other birds -- including its distant relative, the Western scrub jay.

"The big difference is that they have a cooperative breeding system," Breininger said.

"Their kids stay with them, often for years, helping their parents watch out for predators, defend their territory and feed future generations of young. They're in evolutionary and ecology textbooks around the world because the cooperative breeding system is considered fairly unusual."

Breininger, leader of the ecology program's habitat assessment group, has researched Florida scrub jays for 30 years. He and colleagues Geoff Carter and Stephanie Legare, both of IHA, and Jim Lyon of the U.S. Fish and Wildlife Service work together to study the birds and their scrubby habitats, and to help with the decision-making process in endangered species habitat management.

The Florida scrub jay was added to the endangered species list in 1987 and is classified as threatened, meaning it's not yet at the brink of extinction, but likely will be in the near future. Preserving, restoring and maintaining the bird's remaining habitat is the key to saving the species.

The 140,000-acre Merritt Island National Wildlife Refuge overlays the space center on central Florida's east coast. Roughly 300 Florida scrub jays call the refuge their home. But the bird's statewide population continues to decline, due not only to habitat loss, but also to the overgrowth and unsuitability of the habitat that remains. Florida scrub jay populations across the state have generally been declining by 25 to 65 percent per decade.

Florida scrub jays live in families numbering between two and eight birds. They eat small vertebrates and insects during most of the year. In the fall, each jay will cache 6,000-8,000 acorns in open, sandy areas, and the family will rely on this private stash when temperatures drop in the winter.

A breeding pair mates for life and makes a home in a territory typically encompassing about 25 acres of land. One bird will serve as a sentinel, keeping an eye on the family's territory to defend it against intruding scrub jays or, more importantly, predators. If a threat is detected, the lookout bird makes a telltale "ground predator call" and territorial boundary lines are temporarily abandoned as all the able-bodied jays in the area converge on the intruder, mobbing it until it leaves.

"The landscape's full of early warning systems," Breininger explained.

"If a predator's coming through that landscape, and the scrub is nice and open so the jays can see well, you can hear them calling to each other. They know what's happening."

Many of the scrub jay's predators are natural: the Cooper's hawk that stealthily glides into the scrub undetected or the snakes that prey on jays' nests, devouring the unhatched eggs and nestlings.

The jays have to defend against these threats every day. But the loss of their habitat and the degradation of what's left are wider-scope, systemic problems. When scrub land becomes unsuitable, the impact shows in declining recruitment, the number of young who've survived to become adults. 

"Their mortality rates exceed their recruitment rates, and so populations just gradually wink out," Breininger said.

"We're working on developing strategies to bring back the habitat to where recruitment exceeds mortality rate, so populations can grow."

Scrub refers to ancient beach dunes, a result of changes in sea level, and the surrounding pine flatwoods. Scrub jays need medium-height oaks interspersed with sandy expanses where they can forage, cache their acorns and see predators. These areas have been prime sites for development, and over time, the birds' natural habitat has been fragmented and built upon.

What remains is often thick and overgrown due to decades of fire suppression. The lightning-sparked fires that once occurred regularly across Florida are now put out quickly, before they can spread. The result: thick forests that contain far more fire fuel than normal. Not only can jays not survive in such areas, once the area does burn, the fire is unplanned and difficult to safely contain.

Today, Breininger and many others are working to better understand how to restore these remaining habitats using controlled burns or strategic cutting of overgrowth.

"We recently had all the land managers from east central Florida who have scrub jays come join us for an approach called 'adaptive resource management,' which is a direct integration of science and land management," he said.

This collaborative method brings together scientists, land managers and other stakeholders to agree on an objective and choose the best action to take. But it doesn't stop there.

"You look at the habitat and at the state of the scrub jays, and you make a decision, based on a set of models using past data, about what would be the best management action. Then you perform that action -- it may be no action, burn, cut and burn -- and you measure the response. You then use the response to update your models," Breininger explained.

This repetitive, ongoing process widens the knowledge base, improves models, reduces uncertainty and makes management more efficient and reliable.

"Scrub jays are a management indicator species for a whole group of animals and plants that are not adapted to this overgrown, dense, scrubby-type environment," Breininger said. "Usually if you restore habitat to what's good for scrub jays, you restore an entire ecosystem."

The Florida scrub jay has been a Sunshine State resident for at least 2 million years. With the help of ecologists at Kennedy and across the state, these smart, inquisitive birds will thrive once again.

Close-up of a Florida scrub jay
A breeze ruffles the blue feathers of a Florida scrub jay at NASA's Kennedy Space Center. Roughly 300 Florida scrub jays reside in the Merritt Island National Wildlife Refuge.
Image Credit: 
NASA/Dan Casper
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The Florida scrub jay is similar to a blue jay in color and size, but lacks a crest
The Florida scrub jay is similar to a blue jay in color and size, but lacks a crest.
Image Credit: 
NASA/Dan Casper
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Page Last Updated: April 1st, 2014
Page Editor: Anna Heiney