Crazy About Owls

Karl Kleiner, PhD, associate professor of biology, has been "crazy about owls" since his high school days, and his passion has not waned over the years. Federally licensed to place leg bands on owls, he conducts research and works with other organizations to ensure the future of the Pennsylvania barn owl and the northern saw-whet owl.

Barn Owls

Since the mid-1900s, the landscape in Pennsylvania has changed, leading to a decrease in the population of barn owls. Because they are nocturnal and secretive, little is known about their population numbers and movements throughout the state. A Pennsylvania Game Commission initiative in 2006 led to the banding of barn owls by wildlife diversity biologists. The problem is that adult barn owls are rarely recaptured alive, so leg bands provide limited information on their movement. 

Kleiner is researching another option for tracking the birds – through their DNA. He accompanied the biologists as they banded barn owls, gathering feather samples from which he extracted DNA. 

"The DNA can be copied and sequenced, allowing me to create a family tree of the barn owl nests visited," he said. "In addition, I will be able to track the genetic diversity of Pennsylvania’s barn owl populations."

Kleiner hopes his research will help the Pennsylvania Game Commission and other organizations create management plans to most efficiently prioritize conservation efforts on behalf of the owls. 

"Areas of the state with low genetic diversity might be targets for supplementing the population with owls from different genetic lineages, which would increase reproductive success," he said. "On the other hand, we might find that there is no geographically based genetic structure to the barn owl population in Pennsylvania, suggesting that dispersal of barn owls is high. Under this scenario, conservation efforts might target increasing the barn owl population through increased placement of nest boxes, habitat preservation, education and supplementation of genetically similar owls from captive populations."

Kleiner is also working on a related project that examines the sex ratio of barn owl clutches in relation to food supply. ("Clutch" is used to describe the collective eggs that a bird lays at one time.) The sex ratio of birds is manipulated by the mother, and the sex that is favored in a clutch is a function of resource availability. One hypothesis suggests that under conditions of low food, females should produce proportionally more males per clutch; conversely, proportionately more females should be produced when food availability is high. 

"Unlike animals, you cannot lift the tail of a bird to determine its sex," Kleiner said. "We use molecular techniques on feather samples to observe the differences in the sex chromosomes to determine the sex." 

For his senior thesis research, Ben Heyler '09 developed a faster and less expensive molecular technique for sexing barn owls. Shawn Fauth '10 has refined Heyler's methods for greater consistency, and he is now comparing the sex ratio of barn owl clutches across three consecutive years of sampling.  

Kleiner is using the barn owl population at ZooAmerica in Hershey, Pa., to provide positive controls of owls of known sex to be sure that the methods his students have developed are providing accurate results. His contact at ZooAmerica is Katie Fesler, a 2007 graduate of York College, who serves as a naturalist in the Desert Southwest exhibit.

Through both research projects, Kleiner hopes to keep the barn owl as a common species in Pennsylvania. "The ultimate objective is to help prevent the barn owl from becoming an endangered species," he said.

Northern Saw-Whet Owl

Kleiner and his wife have volunteered at Kings Gap Environmental Education and Training Center in Carlisle since 1999 for a program sponsored by the Ned Smith Center for Nature and Art in Millersburg, Pa. Through the Center, they band and release the northern saw-whet owl to learn more about where and when the birds migrate. 

The saw-whet, which is depicted on the Pennsylvania Conserve Wild Resources license plate, is a small, "very secretive" owl, according to Kleiner. "Years ago, they were thought to be rare or threatened," he said, "but through tracking, we've found that there are actually a lot of them."

Each fall, the team from the Ned Smith Center catch, band and release hundreds of owls – 20 birds is a good night, according to Kleiner – at three banding stations in central Pennsylvania. They lure the owls into mist nets by playing a recording of the male's territorial call, which Kleiner says "sounds like a garbage truck backing up."

After they're captured, the birds are weighed, the sex is determined and noted through wing length and body weight (females have longer wings and are slightly heavier), and various measurements are recorded, including the length of the bill and how much fat they have on their bodies. The age of the owls is determined based on the color of their wing feathers. 

When all of this information has been documented, the birds are fitted with leg bands and released. A few of the owls are also fitted with a tiny radio transmitter that allows researchers like Kleiner to more closely track their movements. 

"Using the radio transmitters, we can track them during the day to map their roost location and study their habitat," he said.

Most of the saw-whet owls breed during the summer in Canada; some breed in Pennsylvania or New York. The banding done at the Ned Smith Center occurs during their migration in the fall, when they travel southward, some going as far as Alabama. The Center's research focuses on that movement. 

"We're trying to answer a number of questions," Kleiner said. "Where are the owls coming from? Are they coming from different breeding grounds or one big area? Is this one genetic population, or are there multiple populations breeding?"

Kleiner has shared his work with the Ned Smith Center with his students at York College, and several of them have had the opportunity to participate. During last fall's banding, biology major Victoria Kentner '09, who was taking Kleiner's ecology course, accompanied him to the Center to assist with the banding program. 

"As a biology major, I would love to pursue field research as a living, so getting some hands-on experience helped me determine a possible career path," she said. "Even without this motive, I would still volunteer, because these owls are adorable and I genuinely enjoy this type of research."