By Scott Prater
Around this time every year, Schriever gains some new residents. They fly in from distant parts of the continent, chase current residents out of their homes and raise their own offspring before departing again in late autumn.
The federal and state governments actually prefer these seasonal residents to full-time inhabitants, even going so far as to protect them from harm.
Most people who’ve been at Schriever for more than a year have heard of them. They’re known as western burrowing owls; they’re due back at Schriever any time now and the 50th Civil Engineer Squadron Environmental Flight has developed its annual protection campaign to safeguard the threatened species while they take up temporary residence here.
Given their small stature, it may be surprising to learn these birds fly thousands of miles from their winter abodes in areas of New Mexico, Texas, Arizona and even as far as Mexico. Once here, they chase black-tailed prairie dogs from their established burrows, then use those to mate and care for their young for a few months before migrating back.
The birds are covered under the Migratory Bird Act by the federal government, as well as in an Air Force Instruction. So, steps need to be taken to protect them and their habitats.
“That the western burrowing owls keep returning to Schriever to nest and successfully raise offspring year after year is a good indication that we’ve retained enough biodiversity on base to sustain this state-endangered species,” said Al Fernandez, 50th Civil Engineering Squadron environmental engineer. “It may also be a good indicator that we have been practicing good stewardship of our installation, especially the still-undeveloped portions that the owls prefer to nest in.”
The 50 CES Environmental Flight is in charge of protecting the birds while they’re here, which could last until Nov. 1 according to Andrew Jensen, 50 CES Environmental Flight chief. That’s when the Colorado Department of Wildlife has designated as the end of the owl’s nesting season.
Jensen hasn’t seen any western burrowing owls here yet, but in past years, they’ve commandeered prairie dog burrows at several sites on base, usually on the south side near the Base X training area. The owls typically mate and care for their young for a few months, until they decide the fledglings can survive on their own.
Since they’re a protected species, their presence can often delay or impede construction plans or transportation in the vicinity of the designated burrows. During 2009, owl nests near the child development center delayed construction of the center’s expansion, but for the past two summers, they’ve commandeered prairie dog burrows in less populated areas.
Government regulations specify that no physical harm should be caused to either the birds or their natural habitat. Those same governmental agencies don’t provide specific requirements or protocols for organizations to meet compliance, but the Colorado Department of Wildlife does offer a recommendation, which states that a buffer zone of 150 feet should exist between the owls’ nests and any construction or transportation area.
The environmental flight is responsible for monitoring the owls and reporting any violation of Air Force, state and federal regulations concerning the owls. Violations are reported to the U.S. Fish and Wildlife Service and CDOW, who take the matter very seriously and follow through with some sort of punishment.
Environmental flight personnel will erect signs warning everyone to stay out of the protected buffer zones and plans to release a base bulletin, which informs Schriever personnel about the protected birds.
The owls are small, about the same size as the prairie dogs, but they are predatory. They like to eat insects, but once summer turns to fall and the insects disappear, they’ve been known to attack mice and other small invertebrates.
“I’ve even seen pictures of a burrowing owl with a lizard dangling from its beak,” Jensen said. “When I do informational talks on the birds, I’m often asked why they don’t eat the prairie dogs. Then I hold up a prairie dog skull and a replica of a burrowing owl skull. It’s easy to see how the prairie dogs are bigger.”
During the next few months, environmental flight personnel will continue to monitor the base for owl nests. In the meantime, CEV seeks to make people here aware of the potential for more burrowing owl sites, even as numbers for the birds diminished significantly last year. Jensen said as many as 40 owls called Schriever home in 2011, but he noticed only one bird last year.
“Maybe we just experienced an anomaly,” Jensen said. “It will be interesting to see how many show up this year. It could be an indicator as to whether their numbers are shrinking or not.”
The owls typically migrate south again in late September.
“One day they’re all here and then suddenly, they’re gone,” Jensen said. “The prairie dogs typically jump back into those same burrows a week later.”
For more information on western burrowing owls and the protections afforded to them contact the 50 CES Environmental Flight at 567-3360.