Animal Field Guide

Burrowing Owl

Athene cunicularia
(Strigidae)

Montana Species of Concern
Global Rank: G4
State Rank: S2B

Agency Status
USFWS:
USFS: SENSITIVE
BLM: SENSITIVE

Burrowing Owls are probably most distinguishable because of their ground-dwelling behavior. They may also be identified by their long legs, round, tuft-less head, and bright yellow eyes. The distinct oval facial ruff is framed by a buffy white eyebrow-to-malar stripe near the bill (Haug et al. 1993). The primary feathers of their relatively long, rounded wings are brown with buffy-white barring. Their tail is short and also decorated with this same brown with buffy-white barring. The back, scapulars, and crown are brown with buffy-white spotting (Haug at al. 1993). The underparts are a buffy-white with broad brown barring, while the throat and undertail coverts are white (Haug et al. 1993). The bill is pale, cream colored to yellowish-white or greenish-yellow (Haug et al. 1993). As with other owl species, females may be darker than males, especially in worn plumage. Juveniles are similar to the adults, except the head is plain brown, the upper chest has a dark tan band, and the lower chest and belly are light-to-white in color.

This owl averages 24 cm (9.5 inches) long with a wingspan of 53 cm (21 inches), and a weight of approximately 155 grams (5 onces) (Sibley 2000).

The male call is described as a high nasal trumpeting "coo-coo", which may be answered by the female with a short clear "eeep" or a harsh rasping "ksshh" (Sibley 2000). A rasping alarm call is made by both sexes. Vocalizations heard year round include short, sharp husky "chuk" or a series of barking notes, with a rasping scream described as "kwee-ch-ch-ch-ch" or "cheee-twikit-twik" (Sibley 2000).

Burrowing Owls can be identified from other owl species by the fact that they live in the ground. They are found in open grassland habitat where they nest and roost in abandoned animal burrows. In addition to perching on the lip of their prairie burrows, these owls may be observed on fence posts. They are also active during both the day and night. An owl species common in Montana, which also may be seen on the ground, is the Short-eared Owl. This species, however, is about twice the size of the Burrowing Owl, has dark patches on the wings and at the eyes, short ear tufts, a dark bill, and does not nest is burrows (it nests in a scrape in the ground) (Ehrlich et al. 1988).

Burrowing Owls are migratory in the northern portion of their range, which includes Montana. The extreme dates of observation for Burrowing Owls in this state are, at the earliest, March and, the latest, October (Montana Bird Distribution 2003). The majority of the spring reports for this species occur, however, in April with most fall observations in September.

Some U.S./Canadian breeders winter in Mexico and possibly in Central America (James and Ethier 1989). Canadian breeders are believed to winter south of the U.S.-Mexico border.

Burrowing Owls are found in open grasslands, where abandoned burrows dug by mammals such as ground squirrels (Spermophilus spp.), prairie dogs (Cynomies spp.) and badgers (Taxidea taxus) are available. Black-tailed prairie dog (Cynomys ludoviscianus) and Richardson's ground squirrel (Spermophilus richardsonii) colonies provide the primary and secondary habitat for Burrowing Owls in the state (Klute et al. 2003). The burrows may be enlarged or modified, making them more suitable. Burrowing Owls spend much time on the ground or on low perches such as fence posts or dirt mounds.

Burrowing Owls are opportunistic feeders; their diet is varied and may depend upon the time of year. Invertebrates comprise the majority of their diet in most areas, but small mammals, amphibians, reptiles, and birds may also be consumed (Haug et al. 1993).

Burrowing Owls have been found using badger holes in the Bozeman latilong (Skaar 1969). Generally, the reported densities of Burrowing Owls varied from different locations: 8 pairs per square kilometer were found in California; 3.5 to 6 hectares per pair in North Dakota; and 13 to 16 hectares per pair in Saskatchewan.

Territorial defense is mainly limited to the immediate vicinity of nest burrow and individuals may share foraging areas.

Home ranges for Burrowing Owls in Saskatchewan were found to be 0.14 to 4.81 square kilometers; with 95% of all movements within 600 meters of the nest burrow (Haug and Oliphant 1990). Significantly smaller home ranges were reported in Saskatchewan (0.08 to 0.49, average 0.35 square kilometers) during periods of small mammal superabundance (Sissons et al. 1998, Wellicome 1998). Dispersing young use satellite burrows in the vicinity of their natal burrows for about two months after hatching before departing the natal area (King and Belthoff 2001).

The badger plays an important role in the nesting ecology of Burrowing Owls in northern Oregon. This mammalian species provides nest burrows and can be a major predator of Burrowing Owls (Green and Anthony 1989).

Breeding of Burrowing Owls is well documented in the state. Since this owl species is so tied to prairie dogs and ground squirrels, both species occuring primarily east of the Continental Divide, the majority of confirmed breeding records for Burrowing Owls are also east of the Divide (Klute et al. 2003). The nest chamber, located within a mammal burrow, may be lined with horse dung, cow chips, dry grass, pellets, or feathers; they may occasionally be unlined (Ehrlich et al. 1988). Clutch size averages 6 to 7. The female incubates the elliptical (almost spherical at times), smooth, glossy-white eggs (31x26 mm in size) for 27 to 30 days (Baicich and Harrison 1997). The male provides food during incubation and the early nestling stages. The young owls can run and forage at 4 weeks and can sustain flight at 6 weeks. The average number of fledglings per brood is three to five. This species may first breed at one year of age; generally one brood per year is produced.

No specific management activities directed at the conservation of this species in Montana are documented. Recreational shooting of prairie dogs in their colonies, however, has the potential to cause direct illegal mortality to this owl species (Klute et al. 2003). Systematic suppression of prairie dogs by state agricultural agencies reduces Burrowing Owl habitat, but the overall impact of these activities in combination with recreational shooting has not been studied (Klute et al. 2003).