Barn Owls and Barns, Vanishing Parts of Iowa's Past
Originally published in the Fall 2002 issue of the Iowa Barn Foundation Magazine.
Written by Steve Lekwa, Story County Conservation Director.
Those who remember when nearly every section in Iowa supported at least one active farm are middle aged or older, now. The farms of that time were diversified with both livestock and crops on most of them. Livestock meant that a farm had outbuildings, pasture, and hay, as well. The diversified farm provided a habitat for a variety of grassland wildlife, among them one of Iowa's rarer birds, the barn owl.
The barn owl is a mid-sized owl, larger than our native screech owl, but smaller than the barred owl and great horned owl. It is in a genus all its own, with no other relatives. Barn owls are mostly white on the front and have a distinctive "monkey face". Their back is darker with rust colored highlights. They stand 14" to 16" tall and have about a 3 1/2 foot wing span. They have no "horns" or "ears" of feathers on their heads and their eyes are brown. Their voice is more a scream or screech, and they can't "hoot" like most of our native owls. They also make clicking and hissing noises. They feed mostly on mice, particularly the brown meadow mice found in open grasslands. This often gives the oval shaped pellets of hair and bone that they regurgitate a darker color than those of other owls that feed on a wider range of prey.
The barn owl has world-wide distribution, but Iowa has always been at the northern edge of its native range. They don't like the extended cold of northern winters. When habitat was good, though, with plenty of grassland in which to hunt small rodents and old hollow trees and large old buildings to nest in, a few were always able to call Iowa home. The things barn owls need to survive have nearly disappeared as farming has changed in the past few decades, however. Pastures and hay are rare in many parts of the state. Most farms no longer raise livestock, at least in the old ways, and the barns and other buildings that supported those practices are disappearing, as well. Even old hollow trees are often removed to make room for more productive uses of the land.
The Iowa Department of Natural Resources is trying to keep barn owls around as a valuable and beautiful part of Iowa's natural heritage. They tried captive breeding and releasing for a number of years in the mid 1980's with over 400 young owls stocked in likely looking habitat where it could still be found. Barn owls, unlike most of our other native owls, can raise large families. Great horned owls seldom lay more than two eggs, but barn owls lay 3-11 eggs at a time. They also nest over a longer season of the year. Barn owl sightings increased a little bit for a while, probably due to increased publicity about the program, but confirmed nesting attempts varied from 0 to only 5 in the same period. Biologists placed tiny radio transmitters on 36 released owls in 1985. Twenty-four of the newly stocked birds perished in the first 60 days, and thirteen of them appeared to have been killed and eaten by great horned owls.
It's wild, naturally reproducing birds that are the measure of a stocking program's success, and the IDNR finally ended the captive breeding program. They shifted the program's emphasis from stocking birds to placement of secure nesting boxes in areas where owls have been seen. The nesting boxes help to maximize nesting success when they are used. Some nesting attempts in old barns without boxes lost eggs and/or young when they fell from the narrow barn beams, or when the eggs or young were eaten by other predators. Most of the nesting boxes are placed in old barns in areas with extensive CRP grasslands. They serve to keep the eggs and young in the nest and protect them from predators.
1995 was a banner year for the barn owl program. 12 nests were recorded, with 7 of those in boxes provided for their use. 1996, however, showed how vulnerable barn owls are to factors beyond human control, and no successful nests were found. Recorded barn owl nest attempts since 1996 have varied from two to six per year, and none were found in 2001. Most reported nests are found in southern and southwestern Iowa areas with large acreages of conservation reserve grasslands.
The barn owl is endangered in Iowa and in surrounding states, meaning it is very close to disappearing entirely. The Iowa Department of Natural Resources continues to work for its survival with the limited resources provided by the state's Wildlife Diversity (nongame) Program based at the old Ledges State Park research station south of Boone. They are most interested in barn owl sightings anywhere and more interested yet in possible nesting attempts. The IDNR can be reached by calling 515-432-2823.
Barn owls still show up here and there in Iowa, but this beautiful and beneficial bird is hanging on by only a thin thread. A weak and starving individual was found in Story County in 2001 but could not be saved. Old barns near extensive grasslands could be a key to survival of the species as part of our natural heritage. If you know of such a place, and if you are lucky enough to see or even hear a barn owl nearby, the IDNR would like to know. Plans for nesting boxes and directions on their placement are available from the IDNR, and possibly your local county conservation board as well.