Wild Animals and Old Barns
Originally published in the Fall 2004 issue of the Iowa Barn Foundation Magazine.
Written by Steve Lekwa, Director, Story County Conservation
Barns have been built to shelter domestic livestock and harvested crops for thousands of years. It's safe to assume that at least some wild animals didn't see these intrusions into their habitat as necessarily bad things either. Shelter and food are at the top of their priority list, too, and barns provided both.
It's likely that the first wild creature to move into a barn was a lowly mouse or rat. They had already figured out that food was usually more plentiful around people, and this new type of building often held lots good things to eat. At the very least, it offered good places to hide. Other creatures probably weren't far behind the rodents.
Rodents occupy the low end of the food chain, and, as such, are primary menu items for predators large and small. Concentrate rodents in and around a barn, and it's certain that predators will follow. An earlier article in this series discussed how attractive barns are to owls, but many four-legged animals look to barns for good hunting or maybe a cozy den site, too.
Purely predatory animals eat only meat, and a few of these that might show up around old barns are weasels, shrews, and badgers. They will be looking primarily for mice or other smaller prey to eat, but a badger might dig a den under a barn. If the barn is still home for larger prey-- poultry, little pigs, or sheep--it may attract the attention of larger predators like a fox or coyote. Although wary of being around people, these intelligent predators often figure out that it's pretty easy to catch a meal inside a farm building if there's a way to get in.
Some Iowa wild animals are not purely predators. They eat what ever then can find, and are known as omnivores (just like us). Barns are very attractive to a well known member of this group, the raccoon. These intelligent and persistent creatures will find a way to get to food they want if there is even the slightest chance of success. They also love old hay lofts as places to raise a family of young ones or just snuggle in for the winter. Raccoons are not particularly clean animals in spite of their reputation for washing food. Their feces often fowls livestock feed, and is loaded with intestinal parasite eggs. One, the raccoon round worm, can even be lethal to humans if untreated. Children should be warned not to play in areas fowled with raccoon feces, and people should wash their hands after handling hay or other things that may have been contaminated with it.
Skunks and opossums also frequent old barns for much the same reasons, food and places to hide. Old foundations seem to attract den diggers like skunks, badgers, and another common wild animal, the wood chuck. The wood chuck, an herbivore, eats only plant material, and will find its food out in the open. A heavy stone or concrete roof over the den seems to be an attractive option for a wood chuck looking for a new home.
Of the animals mentioned, the raccoon is probably the most problematic, especially if the old barn it has chosen is still being used for other purposes by its owner. Mice and rats can be problems, too, but it's almost impossible to keep them out for any length of time. Predators may visit, but usually won't stay around. They're actually allies is the eternal fight against rodents.
Other great allies in humanity's war on rodents are several species of snakes, including the common bull snake, fox snake, and racers. They grow large enough to prey on a rat, but are not poisonous. They, too, will enter buildings in search of prey. Crumbling old foundations also give them access to underground areas below the frost line where they must go to hibernate for the winter.
As you can see, even a long-abandoned old relic of a barn can still offer room and board to a wide variety of our native wildlife.