American Barn Owl

American Barn Owl. 

Other Names : 

• Lechuza Común Americana (Spanish)
• Effraie d'Amérique (French)

 

The American barn owl (Tyto furcata) is usually considered a subspecies group and together with the western barn owl group, the eastern barn owl group, and sometimes the Andaman masked owl, make up the barn owl, cosmopolitan in range. The barn owl is recognized by most taxonomic authorities. A few (including the International Ornithologists' Union) separate them into distinct species, as is done here. The American barn owl is native to North and South America, and has been introduced to Hawaii.

 

Description: 

The American barn owl is a medium-sized, pale-coloured owl with long wings and a short, squarish tail. However, the largest-bodied race of barn owl, T. f. furcata from Cuba and Jamaica, is also an island race, albeit being found on more sizeable islands with larger prey and few larger owls competing for dietary resources. The shape of the tail is a means of distinguishing the barn owl from typical owls when seen in the air. Other distinguishing features are the undulating flight pattern and the dangling, feathered legs. The pale face with its heart shape and black eyes give the flying bird a distinctive appearance, like a flat mask with oversized, oblique black eye-slits, the ridge of feathers above the beak somewhat resembling a nose.

The bird's head and upper body typically vary between pale brown and some shade of grey (especially on the forehead and back) in most subspecies. Some are purer, richer brown instead, and all have fine black-and-white speckles except on the remiges and rectrices (main wing feathers), which are light brown with darker bands. The heart-shaped face is usually bright white, but in some subspecies it is brown. The underparts, including the tarsometatarsal (lower leg) feathers, vary from white to reddish buff among the subspecies and are either mostly unpatterned or bear a varying number of tiny blackish-brown speckles. It has been found that at least in the continental European populations, females with more spotting are healthier than plainer birds. This does not hold true for European males by contrast, where the spotting varies according to subspecies. The beak varies from pale horn to dark buff, corresponding to the general plumage hue, and the iris is blackish brown. The talons, like the beak, vary in color, ranging from pink to dark pinkish-grey and the talons are black.

On average within any one population, males tend to have fewer spots on the underside and are paler in color than females. The latter is also larger with a strong female T. alba of a large subspecies weighing over 550 g (19 oz), while males are typically about 10% lighter. Nestlings are covered in white down, but the heart-shaped facial disk becomes visible soon after hatching.

In the United States, dispersal is typically over distances of 80 and 320 km (50 and 199 mi), with the most travelled individuals ending up some 1,760 km (1,094 mi) from the point of origin. The barn owl has been successfully introduced into the Hawaiian island of Kauai in an attempt to control rodents; however, it has been found to also feed on native birds.

 

Behaviour and ecology:

Like most owls, it is nocturnal, relying on its acute sense of hearing when hunting in complete darkness. It often becomes active shortly before dusk and can sometimes be seen during the day when relocating from one roosting site to another. Barn owls are not particularly territorial but have a home range inside which they forage. Female home ranges largely coincide with that of their mates. Outside the breeding season, males and females usually roost separately, each one having about three favoured sites in which to conceal themselves by day, and which are also visited for short periods during the night. Roosting sites include holes in trees, fissures in cliffs, disused buildings, chimneys and haysheds and are often small in comparison to nesting sites. As the breeding season approaches, the birds move back to the vicinity of the chosen nest to roost.

 

It is a bird of open country such as farmland or grassland with some interspersed woodland, usually at altitudes below 2,000 metres (6,600 ft) but occasionally as high as 3,000 metres (9,800 ft) in the tropics. This owl prefers to hunt along the edges of woods or in rough grass strips adjoining pasture. It has an effortless wavering flight as it quarters the ground, alert to the sounds made by potential prey. Like most owls, the barn owl flies silently; tiny serrations on the leading edges of its flight feathers and a hairlike fringe to the trailing edges help to break up the flow of air over the wings, thereby reducing turbulence and the noise that accompanies it. Hairlike extensions to the barbules of its feathers, which give the plumage a soft feel, also minimise noise produced during wingbeats.

 

Data Source & Credit: Wikipedia