Many times the common name of an animal or bird reflects a distinguishing characteristic of that creature. That is the case with the burrowing owl (Athene cunicularia). The owl shelters itself and its young in holes in the ground dug by itself or other animals. Wherever prairie dogs, kangaroo rats, squirrels, tortoises, armadillos, skunks or chipmunks have abandoned burrows, you may find burrowing owls which have taken up residence.
This owl species lives in grassland or desert areas of Central and South America and western North America, especially in northern California and the northern Great Plains. Southern and central Florida also has year-round populations of burrowing owls in open and dry regions. Florida owl populations tend to dig their own burrows rather than inhabiting abandoned holes.
Winter is breeding season for the burrowing owl. Breeding grounds are mainly in western Texas and especially the Panhandle region. From April to mid-May the nests will have eggs or owlets in them.
Where Owl and Human Populations Intersect
Because of the open nature of the terrain, nests are sometimes found on farmland, cemeteries, vacant land, golf courses, roadsides and airports. This interaction with civilization has led to the decline of burrowing owl populations because of the loss of burrows in which to live and raise their young. The use of insecticides on land utilized by humans not only kills one of the main sources of food for the burrowing owl but also harms or kills the owl itself.
Burrowing owls have been accidentally killed when they hunt along roads during the day and night. While the owl has a few natural enemies like skunks, weasels, hawks and badgers, domesticated dogs and cats also contribute to the population decrease. Where burrowing owls have access to fields in which farm animals graze, they use cow and horse dung around the entrance to their burrow. It is thought the scent prevents predators from discovering the nest.
This owl species tends to live in colonies, another factor in the population decline. For a burrowing owl colony to exist, it must have a large enough space in which to nest and locate food. Each owl requires one acre of land although inhabited burrows can be as close as 46 feet. Plowing and land development leave the owl colonies with too little land on which to nest and breed.
Conserving Burrowing Owl Habitat
In 1985, an effort was made in South Dakota, western Minnesota and Iowa to reintroduce and increase the population. In Minnesota and Colorado, the burrowing owl is on the endangered species list. This is also the case in the Canadian provinces of Alberta, Saskatchewan, British Columbia and Manitoba. In Florida’s Flamingo Gardens Everglades Wildlife Sanctuary, the burrowing owl has been reintroduced with success.
Artificial burrows have been used with some success. Sometimes entire owl populations have been relocated from land scheduled to be developed to places where the burrowing owl once existed but had declined.
Canada banned the use of carbofuran, an insecticide used on agricultural lands after it was found to harm the owls.
A study done by University of Florida researchers in 2004 seems to indicate burrowing owls reproduce more successfully in burrows made by vizcachas rather than those made by hairy armadillos. The study also stated that fire seemed necessary because it burned vegetation like shrubs to a height the owl needed for perching and swooping down upon its prey. Burrowing owls tend not to be in areas where there are trees.
Other studies of the habitat of the burrowing owl has been done by the Texas Breeding Bird Atlas Project, the Oregon State University Department of Fisheries and Wildlife and The Raptor Research Foundation, Inc.
Animal Diversity Web: Athene culicularia: burrowing owl http://animaldiversity.ummz.umich.edu/site/accounts/information/Athene_cunicularia.html
The Wild Ones Animal Index: Burrowing Owls http://www.thewildones.org/Animals/burroOwl.html
Cornell Laboratory of Ornithology, James Coe: Burrowing Owl http://www.birds.cornell.edu/BOW/burowl/
Burrowing owls and burrowing mammals http://www.wec.ufl.edu/faculty/BranchL/research/Branch%20papers/Burrowing%20owls%20and%20%20mammals_Oikos.pdf
Texas Breeding Bird Atlas Project, Sandra Skrei, 2006: Burrowing Owl http://txtbba.tamu.edu/accounts/buow/buowacc.html
Oregon State University Department of Fisheries and Wildlife, 2009: Ecology and Management of Burrowing Owls in California http://people.oregonstate.edu/~rosenbed/California.html
The Raptor Research Foundation, Inc., 1993: Nesting Habitat Use By Burrowing Owls in Colorado http://elibrary.unm.edu/sora/jrr/v027n04/p00175-p00179.pdf