Iowa State has a big animal problem on campus – rabbits.

The small furry mammals are destroying bushes and trees as they forage for food around campus.

“The problem can’t really be controlled,” said James Pease, assistant professor of animal ecology. “We have had two mild winters in a row, and this past winter was the toughest and had the longest snow coverage. It was because the campus was so covered in snow and ice that the rabbits ate things they normally do not eat.”

Rabbit damage has affected all parts of campus.

“The damage is all over campus.” said William Messina, temporary instructor of horticulture. “You can see it next to the Food Science building, at the corner of the Knoll, behind the Farmhouse Museum and the Communication building next to Molecular Biology. At the Communication building, you can see where the rabbits stood on four feet of snow to eat on the bark of the crabapple trees. The rabbit damage is all around.”

Pease said rabbits eat herbaceous vegetation, and in the winter they eat smaller, smooth bark, one centimeter to one-and-a-half centimeters in width.

This winter they ate the smooth bark of larger shrubs, he said.

Although winter conditions led the rabbits to eat shrubs, it could also affect the rabbit population.

“This winter will cut back on the rabbit population because they did not have much to eat this year,” Messina said. “On the Iowa State campus, the rabbits do not have any real enemies except for students and the students’ dogs that are brought on campus.”

Pease said shrub damage could be prevented by putting fencing around the shrubs, but it does not seem cost-effective. Foul-smelling or foul-tasting repellents also are available.

Some plants also have built-in repellents, which are harmful to the digestive systems of rabbits, Messina said, but if they are used too much or too widely, the rabbits will build a tolerance.

Damaged shrubs can be helped by sawing them off at the ground and letting them regrow. Messina said ornamental shrubs were primarily affected.

He said it may take awhile for them to grow back to size, or the shrubs may have to be dug out and replaced.

“All we can do is hope for a mild winter next year,” Pease said. “We share the campus with other wildlife species, and they are not always going to do what we want them to do.”