Great Horned Owl - Bubo virginianus
Bubo virginianus showing prominent ear tufts and yellow eyes (James Stachecki, www.arkive.org)
Description
Great Horned Owl showing barred plumage (Lynn Stone, www.arkive.org)
The Great Horned Owl is a relatively large, brown-coloured owl with conspicuous ear tufts (Mikkola 2012). Both sexes are typically identical in appearance, but females may be about 700g heavier than males (Mikkola 2012). They have large, densely feathered feet and lemon yellow eyes (Mikkola 2012). They typically live in woodlands, hunting a variety of small mammals (Mikkola 2012).
Identification
Height: 45-64 cm
Weight: 900-2503g
Call: deep booming hoots over intervals of several seconds, hu-hu hooooo hoh-hoh
Plumage: large prominent ear tufts present, feathers are warm brown to yellow mottled throughout with greyish brown, black and white. Flight and tail feathers have light and dark bars throughout. Throat is white, which is noticeable during calling. Rusty brown facial disc with white eyebrows. (Mikkola 2012).
Geographical Range
Map showing geographical range of Bubo virginianus. (Mikkola 2012)
This species has a great range, being found throughout most of North and Central America down into parts of South America. Within this geographical range there are 13 subspecies varying in size, with overall size decreasing to the Southern most parts of the range. They are also found at a wide variety of elevations, from sea level up to 4500m in the Andes. Avoids primary rainforest and dense cloud forest. (Mikkola 2012)
Habitat
Lives mainly in open woodlands, swamps, second growth forest and rocky areas with scrub (Mikkola 2012). Great horned owls will nest in tree cavities or nests previously occupied by tree living vertebrates (Jackson, Thompson and Dinsmore 1996). Breast feathers are used to line the nest to insulate young (Jackson, Thompson and Dinsmore 1996).
Life History
Owls will pair up and roost together in December, with courtship beginning in January (Jackson, Thompson and Dinsmore 1996). The male will click his beak, go through long periods of hooting and bring food to the female, until she agrees to copulation (Jackson, Thompson and Dinsmore 1996).
Mid-february 1 to 3 eggs are laid in the nest, which are incubated mostly by the female for the next 28 days (Jackson, Thompson and Dinsmore 1996). Nestlings are not fully feathered for 8 weeks, so they remain in the nest during this time (Jackson, Thompson and Dinsmore 1996).
From 10 to 12 weeks, young will begin flying and start hunting on their own by August (Jackson, Thompson and Dinsmore 1996). Offspring will remain within ther parents territory until they disperse throughout October to January (Jackson, Thompson and Dinsmore 1996).
Great Horned Owl chicks in tree nest begging for food (Diane McAllister, www.arkive.org)
Great Horned Owl eggs in nest (Leonard Enterprises, www.arkive.org)
Burrowing Owl - Athene cunicularia
Identification
Height: 19-25cm
Weight: 120-250g
Call: hollow, coo-coo oo, repeated over intervals of several seconds.
Plumage: Body brownish mottled with white spots, flight feathers are barred light and dark with tail having only 3 or 4 bars. Pale brown facial disc with distinct white band along throat. Prominent white eyebrows present. White yellowish underparts with dark brown banding throughout. (Mikkola 2012)
Adult Athene cunicularia (left) with young (right) (Tom Lazer, www.arkive.org)
Description
The Burrowing Owl is a small, bird of prey lacking ear tufts and an occipital face with exceptionally long, bare legs (Mikkola 2012). Like the Great Horned Owl, females are also larger than males by about 30g (Mikkola 2012). They live in burrows in open areas and feed on insects and occasionally small mammals and reptiles (Mikkola 2012).
Juvenile Burrowing Owl (Tom Lazar, www.arkive.org)
Geographical Range
The range map to the right shows that this small owl can be found over a large area, including most of America, extending down throughout South America. This species can also be found living in Florida and parts of the Caribbean. Over this range, there are 15 subspecies of Athene cunicularia, all varying in size and plumage colour. (Mikkola 2012)
Map showing the geographical range of the Burrowing Owl (Mikkola 2012).
Habitat
Life History
Found commonly in deserts, savanna, grasslands, pasture land and other open country (Mikkola 2012). They can also be spotted on developed land, such as airports, city gardens and golf courses (Mikkola 2012). They prefer habitat unmodified by man, but commonly live in close vicinity (Coulombe 1971).
These owls will either dig out their own burrows or modify existing ones created by other animals, such as the prairie dog, badgers and fox (Jackson, Thompson and Dinsmore 1996). The usual burrow slants downward at a shallow angle with a surface opening of around 20cm in diameter, but may be as large as 80cm across (Coulombe 1971).
The burrow is lined with dried plant material or manure, which disguises the scent of the nest while keeping it insulated (Jackson, Thompson and Dinsmore 1996).
Territorial and courtship behaviour begin in January for this species (Jackson, Thompson and Dinsmore 1996). During courtship the pair will stand on a mound outside the chosen burrow and proceed to preen each other, rub bills and make soft "kow kow" sounds to one another (Jackson, Thompson and Dinsmore 1996). Like the Great Horned Owl, the male Burrowing Owl will also present food to the female with copulation following the nuptial gift (Jackson, Thompson and Dinsmore 1996). The pair will stay together over several years, or be replaced if one mate leaves (Jackson, Thompson and Dinsmore 1996).
The female lays 6 to 11 eggs in the assembled nest, with 7 to 9 being common (Jackson, Thompson and Dinsmore 1996). She will remain in the burrow approximately 32 days for egg incubation (Jackson, Thompson and Dinsmore 1996). 10-14 days after hatching, the young will make their first appearance out of the family burrow (Jackson, Thompson and Dinsmore 1996). A week after emergence young will begin running and flying after 4 weeks (Jackson, Thompson and Dinsmore 1996).
Offspring will remain by the family burrow until about September, when the family unit moves to different burrows and disperses (Jackson, Thompson and Dinsmore 1996).
A Burrowing Owl peers out from its underground den (Tom Vezo, www.arkive.org)
Young Burrowing Owl chick (Phyllis Greenberg, www.arkive.org)