Family Photo

Burrowing owls often nest gregariously, and are strongly associated with Black-tailed prairie dog (Cynomys ludovicianus) towns. These birds tend to use recently abandoned burrows in which to nest. Black-tailed prairie dogs construct densely packed burrow openings, and control vegetation around the burrow more than other species. MacCracken et al. (1985) reported that burrowing owls nest in vacant prairie dog burrows that are in early stages of plant succession where vegetation height is lower than surrounding prairie. Their study also reported that cover of buffalograss (Buchloe dactyloides) was greater at burrows used for nesting than that of undisturbed prairie, while blue grama (Bouteloua gracilis) cover was dominant at burrows not used for nesting. They concluded that this discrepancy was cause by recent prairie dog activity. Because of the lack of later successional vegetation around a burrow when chosen as a nest, the growth of annual forbes during the breeding season is actually increased. This increased rapid growth actually serves to provide greater cover for emerging owlets. Newly abandoned nests will also be in better condition than older nests (less cave-ins, less litter, etc.) (MacCracken, 1985).

Burrows used for nesting tend to be in soils with a greater sand content than burrows not used (MacCracken et al.,1985). This may be attributed to the increased ease of burrow digging and repair by owls, which use their legs and beak to dig. Voous (1988) reported that burrowing owls are able to excavate burrows of up to 2.5m in length without the assistance of burrowing mammals. Burrows dug by owls in sandy soils have been found Florida, Chile, Aruba, and Columbia (Voous, 1988).

Burrows of other species occasionally used by owls include white-tailed prairie dogs Cynomys gunnisoni), rock squirrels (Citellus variegatus), woodchucks (Maomota monax), marmots (Marmota spp.), northern pocket gophers (Thomomys talpiodes), badgers (Taxidea taxus), skunks, swift foxes (Vulpes velox), coyotes (Canis latrans), raccoons (Procyon lotor), armadillos (Dasypus novemcinctus) (Voous, 1988), and others.

The parents often disguise the presence of a nest by littering the entrance with the scat of predators such as coyotes (Voous, 1988). Anywhere from one to twelve eggs are laid in the disguised burrow (Voous, 1988). Young can hatch up to 24 hours apart from each other. The hatching lag time between eggs leads to an emergence lag time between chicks, and it can often take a week for the entire brood to emerge from the burrow once they have begun. Young spend time huddled at the opening of the nest burrow, waiting to be fed by the parents, both of which share the brood raising responsibilities. Once the young are old enough to hop along the ground, the male may move half the clutch to another nearby hole, where he will house and feed them. Both parents will continue to feed the brood, offering insects, reptiles, mice and gophers, and even prairie dog pups and rabbits (Voous, 1988). Young will gradually wander farther and farther from the nest, ducking back down the hole when danger presents itself. Within a month the nestlings are able to fly and the parents begin to leave them to fend for themselves.