Barn Owl
Tyto alba
Summary 2
The barn owl (Tyto alba) is the most widely distributed species of owl, and one of the most widespread of all birds. It is also referred to as the common barn owl, to distinguish it from other species in its family, Tytonidae, which forms one of the two main lineages of living owls, the other being the typical owls (Strigidae). The barn owl is found almost everywhere in the world except polar and desert regions, Asia...
Behaviour 3
Barn owls communicate with vocalizations and physical displays. Owlets still in the nest utter several distinct vocalizations, including a twitter used to express discomfort, attention-seeking, and when quarreling with nestmates. Young also give a raspy snoring food call. Adults use a variety of vocalizations, including the advertising call, a drawn-out gargling scream that is probably the best known call. The distress call is a series of drawn-out screams. Other vocalizations include a defensive hissing sound, a fast, often prolonged, twitter for feeding, and an explosive yell that is usually directed at a mammalian predator. Also, greeting and conversational twitters seem to convey recognition of mate and accompany various courtship activities. Barn owls are much less vocal when not breeding.
The ability of barn owls to locate prey by sound is the most accurate of any animal tested. This very acute sense of hearing allows barn owls to capture prey hidden by vegetation or snow. Their amazing ability to locate prey using sound is aided by their asymmetrically placed ears. This asymmetry allows these owls to better localize sounds generated by prey. Their ears are extremely sensitive and can be closed by small feathered flaps if the noise level is too disturbing. Barn owls also have excellent low-light vision.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Conservation status 4
Barn owls are protected under the U.S. Migratory Bird Treaty Act and under CITES Appendix II. They are not federally threatened or endangered in the United States, but they are protected in some individual U.S. states--including Michigan, where they are considered endangered.
Threats to barn owl population include climatic changes, pesticides, and changing agricultural techniques. Climate in northern regions is causing snow to last for longer periods, making winter living difficult for the species. Unlike other birds, barn owls do not store extra fat in their body as a reserve for harsh winter weather. As a result, many owls die during freezing weather or are too weak to breed in the following spring. Pesticides have also contributed to declines in this species. For unknown reasons, barn owls suffer more severe effects from consuming pesticides than other species of owls. These pesticides are often responsible for eggshell thinning in females. Another major factor limiting population growth is modern agricultural methods. Traditional farms with many small structures favored barn owl populations. In modern farms, there is no longer an adequate amount of farm structures for nesting, and farm land can no longer support a sufficient population of rodents to feed a barn owl pair. The barn owl population, however, is declining only in some localities, not throughout the range.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: appendix ii
State of Michigan List: endangered
IUCN Red List of Threatened Species: least concern
Sources and Credits
- (c) Patricia van Casteren, some rights reserved (CC BY-NC-ND), http://www.flickr.com/photos/11652635@N00/208477821
- Adapted by c michael hogan from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Tyto_alba
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31428723
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31428729
