Thai post issued a set of new postage stamps featuring owls.
Owls are a group of birds known for their distinct calls, nocturnal habits and silent flight. Owls are familiar to many people because they are often depicted in various ways in popular culture. They rank on par with bats and spiders as the most celebrated of Halloween creatures. Owls also appear as wise and noble characters in many children's stories, including Winnie the Pooh, Mrs. Frisby and the Rats of NIMH and Harry Potter.
Owls belong to a group of birds that includes about 205 species. These species are sorted into two basic groups, the barn owls and the true owls.
Barn owls have a heart-shaped face, long legs and powerful talons. Barn owls are medium-sized birds. There are 16 species of barn owls, including the greater sooty owl, Australasian grass owl, ashy-faced owl, barn owl and Sulawesi owl.
True owls are more diverse than barn owls, with nearly 190 species in about 23 genera. Some better known true owls include screech owls, horned owls and saw-whet owls.
True owls vary in size from the tiny elf owl to the bulky Eurasian eagle owl. True owls have a round facial disc, a short tail and a large head. Their color is muted (consisting of mostly brown, rust, gray, white and black) and their pattern is mottled, helping to conceal them from both predators and prey.
Owls feed on a wide variety of prey. Their main food source consists of small mammals such as mice, squirrels, voles and rabbits. Owls swallow small prey whole. They must tear larger prey into small pieces before swallowing. They later regurgitate pellets of indigestible material such as bone, fur and feathers.
Most owls hunt at night and in doing so avoid competition with daytime avian hunters such as hawks and eagles. Although nocturnal feeding is the norm for most owls, some species such as burrowing owls and short-eared owls feed during the day. Still other species, such as pygmy owls, feed at dusk or dawn.
Owls are depicted in cave paintings in France that date back 15,000 to 20,000 years. Owls also appear in Egyptian hieroglyphics. They have held a variety of symbolic roles in culture and have represented misfortune, death, prosperity, and wisdom.