The North American Burrowing Owl after a little dinner.
“As Is” photo, no editing.
The Burrowing Owl (Athene cunicularia) is a small, long-legged owl found throughout open landscapes of North and South America. Burrowing owls can be found in grasslands, rangelands, agricultural areas, deserts, or any other dry, open area with low vegetation. They nest and roost in burrows, such as those excavated by prairie dogs Unlike most owls, burrowing owls are often active during the day, although they tend to avoid the mid-day heat. Most hunting is still done from dusk until dawn, when their owl apomorphies are most advantageous.
Males and females are similar in size and appearance. However, adult males sometimes appear lighter in color because they spend more time outside the burrow during daylight, and their feathers become sun-bleached. The average adult is slightly larger than an American Robin, at 25 cm (10 inches) length, 53 cm (21 inches) wingspan, and 170g (6 oz).
The typical who who call of a burrowing owl is associated with territory defense and breeding, and is often given by adult males to attract a female to a promising burrow. They also make other sounds, which are described as chucks, chattering, and screams. These sounds are usually accompanied by an up and down bobbing of the head. When alarmed, young birds will give a hissing call that sounds like a rattlesnake, a case of acoustic Batesian mimicry.
The nesting season begins in late March or April in North America. Burrowing owls are usually monogamous, but occasionally a male will have two mates. Pairs of owls will sometimes nest in loose colonies. Their typical breeding habitat is open grassland or prairie, but they can occasionally adapt to other open areas like airports, golf courses, and agricultural fields. Burrowing owls are slightly tolerant of human presence, often nesting near roads, farms, homes, and regularly maintained irrigation canals.
The owls nest in an underground burrow, hence the name Burrowing Owl. They use burrows created by other burrowing animals such as prairie dogs, ground squirrels, or badgers. If burrows are unavailable and the soil is not hard or rocky, the owls may excavate their own. Burrowing owls will also nest in shallow, underground, man-made structures that have easy access to the surface.
During the nesting season, burrowing owls will collect a wide variety of materials to line their nest, some of which are left around the entrance to the burrow. The most common material is mammal dung, usually from cattle. At one time it was incorrectly thought that the dung helped to mask the scent of the juvenile owls, but researchers now believe the dung helps to control the microclimate inside the burrow and to attract insects, which the owls may eat.
The female will lay an egg every 1 or 2 days until she has completed a clutch, which can consist of 4-12 eggs (usually 9). She will then incubate the eggs for three to four weeks while the male brings her food. After the eggs hatch, both parents will feed the chicks. Four weeks after hatching, the chicks are able to make short flights and begin leaving the nest burrow. The parents will still help feed the chicks for 1 to 3 months. While most of the eggs will hatch, only four to five chicks usually survive to leave the nest.
Site fidelity rates appear to vary among populations. In some locations, owls will frequently reuse a nest several years in a row. Owls in migratory northern populations are less likely to return to the same burrow every year. Also, as with many other birds, the female owls are more likely to disperse to a different site than are male owls.