Analysts shoot for more hoots
November 30, 2006
The burrowing owl is the subject of a Department of Defense study that includes Cannon Air Force Base and other Defense Department installations. (Courtesy Photo)
A single feather holds the biography of a burrowing owl.
The atoms inside can reveal its diet, its source of water, its birth place.
Hoping to unlock the origins and migratory patterns of burrowing owls (so named because they nest in holes in the ground), Carol Finley and her colleagues have collected more than 1,000 owl feathers from military installations across the Southwest.
This summer, more feather samples from owls at Cannon Air Force Base and other installations will be collected, according to Finley, natural resource manager at Kirtland Air Force Base at Albuquerque.
Only about nine inches tall, burrowing owls are a U.S. Fish and Wildlife Service species of concern. The classification precedes inclusion on the endangered species list.
Finley and team, however, have a theory: The owls, rather than declining in number, may have become less migratory.
“It has yet to be determined if (burrowing owls) are dying off,” Finley said, “or just moving to different locations, which is something that could be happening.”
The study, funded by the Department of Defense, has rippling implications.
“It will help identify the management role of the DoD for conserving burrowing owls nesting in the region, potentially help prevent further listing efforts for a species that is common on DoD installations, and provide information on risk and frequency of bird strike hazards by documenting foraging and migratory habits,” reads a document co-authored by Finley.
In the document, Finley and company suggest burrowing owls may have become year-round residents of southwestern U.S. and northern Mexico.
If that is true, reintroducing the owls in areas where their populations have dwindled could be futile, according to one of Finley’s partners, Vicki Garcia, a research specialist with the University of Arizona.
“(If) owls being born migrate south rather than returning to breed in the north ... if they are actually redistributing, these (northern) areas aren’t really stable,” Garcia said.
Areas of heavy agriculture seem to be a magnet for burrowing owls, Garcia said. Near farmed fields, the birds’ prey — insects and small rodents — is more abundant, she said. Homes for the owls, often old prairie dog burrows, are easier to come by.
The agriculture link makes the work of Finley and Garcia more complex.
“If the owls are dependent upon agriculture,” Garcia said, “you have to be careful about saying burrowing owls are abundant.”
Take away agriculture and the birds’ vitality may plummet, Garcia explained.
The burrowing owl study hinges on continued funding from the Department of Defense Legacy Resource Management Program, Garcia said. Pending stable funds, it should be complete in 2008, she said.
Funding and feather samples aside, many behind the study have fallen for the burrowing owl.
“They are a very charismatic bird,” Finley said.
The owl, with its leopard spots and bright yellow eyes, forages in the day and the night, unlike its relatives. Like a pair of stilts, its legs jut from its body, which weighs just about five ounces.
Although male owls chose burrows during breeding season, actual residence requires approval from female owls, Finley said.
“If the female doesn’t like the burrow, they will move to another. It’s kind of almost like humans. If a female doesn’t like the house, they move,” Finley said, with a laugh.
Mostly, it’s the baby burrowing owls that have endeared Garcia to the species.
“(They) all stand around the burrow. They preen each other, play around,” she said.
In their field work, those involved in the study try to soften their intrusions on the owls, they said.
Collecting blood and feather samples from the owls takes just a few minutes, Finley and Garcia said.
Bands are placed around their legs and collars around their necks. Radio transmitters inside the collars track the migration of the birds and the bands identify them.
Once the owls are banded, collared and plucked, they usually re-emerge from their burrows within minutes, Finley sai