SOUTH BEND, Ind. (AP) -- Purdue University researchers studying wildlife interfering with operations at a northern Indiana airport say the problem has diminished but not disappeared.
Tree thickets, standing water, gaps under fences and even runway lights and signs at the South Bend Regional Airport are attracting birds and mammals, according to early observations.
Research technician Jacob Kubel and graduate student Dave Glista began studying the airport's surrounding habitat in April, using spotlights, motion-sensor cameras, log books and their eyes and ears.
Purdue's state-funded study is one of 10 under way at Indiana airports to assess wildlife threats.
South Bend airport officials have called in falconers, bulldozed 48 acres of nearby woods and staged deer hunts. But airport staff still say they are forced to patrol the area every few hours to make sure deer and other creatures do not interfere with flights.
The airport received an $820,000 grant from the Federal Aviation Administration last year to install fencing to keep out the animals. But airport officials would like to hear the study results first.
In Indiana, starlings, mourning doves, killdeer, sparrows, red-tailed hawks and American kestrels account for most of the animal strikes of planes - and South Bend Regional has plenty of those types of birds, the South Bend Tribune reported Tuesday.
A plane at flew into a flock of mourning doves in 1990. Airplanes struck deer in 1992 and 2002.
After finishing their field work in February, Kubel and Glista will crunch numbers, put together special maps of the property and make some suggestions to the St. Joseph County Airport Authority.
Changing one habitat to eliminate an animal can make the land attractive for something else, Kubel said.
''We're trying to find a solution without paving over everything,'' said Kubel, who works for Purdue's department of forestry and natural resources.
Kubel believes deer have been living on the property on and off and they are not eager to leave.
During his last visit, Kubel counted 40 holes under the fences, some large enough to let animals as big as coyotes get through. And some of the fences are not buried deep enough, he said.
Kubel said along the fences, ground squirrels are proliferating, but they do not pose much of a threat. But they draw red-tailed hawks, which can be a threat to airplanes coming and going.
The researchers have spotted many birds including the hawks, turkey vultures, grasshopper sparrows and meadowlarks. Wooden stakes, signs and light poles near the runway draw birds.
''They're great perch sites,'' Kubel said. ''If you're drawing birds next to the runway, if a plane comes whipping in, the bird might panic and fly up.''
Topography also factors in the equation, Kubel said. A lot of smaller airports lease property for agricultural purposes to make money, he said, without much thought of how the sprouting food draws animals.
''If you put the smorgasbord out there, the animals will use it,'' Kubel said. ''No matter what you do, it's hard to eliminate habitat.''
