Pennsylvania tries to track elusive barn owls

By Martha Raffaele. Associated Press.

KLEINFELTERSVILLE, Pa. - State game officials are eager to know how six young barn owls will make their way in the world once they take flight from a nesting box inside a 142-year-old stone barn in rural Lebanon County.

On a recent summer day, the nocturnal creatures hissed loudly in protest - literally not giving a hoot - as a state wildlife biologist and some volunteers rousted them to attach metal bands etched with identification numbers to their legs.

The ritual is being repeated around the state as part of a conservation program the Pennsylvania Game Commission began in September. Barn owls are not considered to be threatened or endangered in Pennsylvania, but officials still worry that suburban development and the growth of large-scale farming are thinning their numbers.

"We don't really know anything about these birds and their migration patterns," said Jamie Zambo, a wildlife diversity biologist who is directing the conservation program. "We're just trying to figure out where they go and what they do, and trying to get a better handle on what we need to do for conservation."

Although barn owls are also not considered a nationally endangered or threatened species, other states have tried to boost their barn-owl populations in recent years, with varying degrees of success.

Barn owls are found throughout the world in regions with warm climates, open grassland and places that provide nesting cavities, such as dead trees, barns and church steeples, said Greg Butcher, director of bird conservation for the National Audubon Society in Washington, D.C.

"We do know that there has been a huge decline in grassland birds as a group ... and most of us feel the barn owl is part of that fleet," Butcher said. "These are birds that did really well up until the 1950s, when agricultural fields were small and people were planting a diversity of crops."

Since then, the owl population has generally declined as small, family farms with vast meadows have given way to larger farms that use more land for crops, and farmers have turned to pesticides to kill rodents on which barn owls prey, such as meadow voles, Butcher said.

Pennsylvania's barn-owl population was well-documented in the 1980s, with 250 nesting locations found between 1983 and 1989, said Dan Brauning, a game commission wildlife biologist who supervises the wildlife diversity program.

"After 1989, we got very few reports throughout the bird-watching networks," Brauning said. "It was our assessment that it was declining severely."

Yet officials left open the question of whether barn owls were endangered or threatened because they are so difficult to track, and they are redoubling their efforts through the conservation program, Brauning said.

"We track over 200 species of nesting birds, and the barn owl is one of a very few that we are not very successful at tracking," he said. "It's scattered across the landscape."

In Iowa, barn owls have been listed as an endangered species since 1977, said Bruce Ehresman, a wildlife diversity technician for the state's natural resources department.

Between 1983 and 1987, the state tried stocking more owls through a captive breeding and release program, but officials didn't experience much success with it, Ehresman said. Part of the problem lies with the state's great horned owls, which prey on barn owls.

"They're extremely aggressive," Ehresman said. "They're known to eat every other owl we have in the state."

The owls have been listed as endangered in Wisconsin for at least 20 years.

"This is a bird that probably in the last two decades, we've had fewer than a handful for sightings statewide," said Dave Sample, a grassland community ecologist for the Wisconsin Department of Natural Resources.

At the same time biologists disagree over whether the bird should even be listed because some believe it was rare in the state to begin with, Sample said.

The birds have experienced a recent rebound in Ohio, said Kathy Shipley a state wildlife biologist. They were listed as endangered from 1990 until 2002, when they were moved to the list of threatened species, she said.

The state began monitoring the owls in 1988 through a program to install man-made nest boxes in barns and other structures near grasslands. The number of nests increased from a low of 12 in 1989 to a high of 56 in 2004, Shipley said.

Officials are not entirely sure how to account for the growth of nests and also need to study the extent to which owls are also nesting in natural cavities, such as hollow trees, Shipley said.

"Are we actually increasing the population, or are we pulling birds from natural cavities into the nest boxes?" she said. "We don't really know what the dynamics are."

...here's hoping the barn owl population can increase...