Owl Pellet Reading
Total Page:16
File Type:pdf, Size:1020Kb
Owl Reading Classification and evolution of owls Owls belong to the phylogenetic class Aves. Two distinct families contain the more than 200 species of owls. The family Tytonidae contains approximately 17 known species of barn owls; the other species belong to the family Strigidae. The oldest known owl fossils are from the Miocene, which occurred 38 to 54 million years ago. Based on the fossil evidence, these ancient owls evolved into the 2 families of modern owls. The oldest barn owl fossils found thus far are estimated to be at least 24 million years old. Fossil evidence indicates that giant barn owls once thrived in the Caribbean and Mediterranean regions between 10,000 and 30,000 years ago. These giants, known as Ornimegalonyx, were 2 to 3 times as large as modern barn owls and twice the size of modern great horned owls. Ornimegalonyx is thought to have preyed upon animals such as the giant sloth and giant rodents such as the capybara, which are over 4 feet long. Ornimegalonyx Great Horned Owl (Present Day Owl) Sight Owls are widely believed to have the best night vision in the animal kingdom. The cat is the only other animal that can come close to the owl's night vision capabilities. Owl eyes function in bright sunlight, too. However, it is believed that owls are not capable of seeing and interpreting a broad spectrum of colors. Owls have extremely large eyes in proportion to the size of their heads. Although owl eyes are well adapted for great visual acuity, there is a drawback. Unlike the eyes of most animals, owl eyes are more flat than spherical in shape. Due to this adaptation, owls have essentially given up the ability for eye movement. Their eyes are fixed in place by a bony structure called a sclerotic ring. As a result, they must turn their heads to move their eyes. However, owls can turn their heads around far enough to see directly behind them. The total range of head rotation for most owl species is an amazing 270 degrees. Hearing Owls have extremely sensitive ears. Owls need this ability to help them find prey that they cannot see with their keen eyes. Owls can hear tiny rodents scurrying around on the ground, even under thick snow. The unique hearing system of owls allows them to pinpoint the location of even the faintest sounds. Their ears are not lined up symmetrically like those of most animals. Having ears that are not lined up even with one another allows the owl to determine precisely from where a sound is coming. Owl faces are shaped elliptically, like a satellite dish. This facial shape, which is very apparent in barn owls and great grey owls, and its facial feathers, allows owls to focus sounds directly on their ears. The elliptical face and offset ears of an owl work together to form a highly sensitive and precise hearing system. Predation Owls are quite specialized predators, having eyes and ears designed to easily locate prey and unique feathers that enable them to fly almost silently. They hunt through the night, mainly consuming rodents and other small animals. Prey is usually consumed whole, but the whole prey is not digested. An owl's digestive tract compresses the undigested portions of the prey, such as fur and bone, into a compact pellet that the owl coughs up and expels through its mouth. Hunting patterns are often developed by owls when they observe their prey coming back to the same place time after time. Great horned owls have been observed making repeated raids on colonies of ducks that return to a specific area to nest. Barn owls sometimes follow a methodical hunting schedule when prey is readily available. They hunt 3 times a day, with the first hunt at around sunset, the second hunt at around midnight, and the third hunt at around sunrise. Diet Owls, like most birds, cannot chew their food and usually eat their prey whole. Most of the time, they do not separate edible parts of the prey from the inedible ones. However, when they have caught something that is too big to swallow whole, they will pick the animal apart before consuming it. Large owls, such as the great horned owl, commonly attack prey near their own size or even larger. Examples include foxes, skunks, weasels, and even smaller owls. The tiny pygmy owl has been known to attack and kill quail, which are twice its weight. Nesting Habits The cavities of rotten trees, or trees hollowed out by woodpeckers often host owl nests. Owls also readily seek out the abandoned nests of other species of birds such as eagles, hawks, or crows. Some owl species also use the cover provided by caves and niches in rocks to provide them with protection from the elements. Great horned owls run squirrels out of their nest, squash it flat, and take it as their own. Once a suitable nesting place has been found, it may be used for many years. When owls do construct their own nests, the quality of workmanship is shoddy at best. Many nests are hastily constructed out of discarded owl feathers and the feathers and fur of their prey. Burrowing owls do try to provide a good nest for their young. These birds nest in holes dug in the ground insulated with grass, plant stalks, and other material, which provides protection for their young. Owls in Society and Culture Throughout history, owls have been linked to unnatural forces, evil, and death. Ancient Babylonians believed that the hoot of an owl at night came to represent the cries of a woman who died during childbirth. In Hungary, the owl was referred to as the bird of death. Owls were official symbols of death for ancient Egyptians. The hieroglyphic for the owl also symbolized darkness, cold, and a state of passivity. Ancient Romans considered the sight of an owl an extremely unlucky omen. According to legend, the only way to negate the effects of this omen was to catch the owl, burn it, and then scatter its ashes in the Tiber River. It has been said that before Julius Caesar was murdered, owls were heard making their mournful cries. However, not all societies and cultures have assigned negative attributes to owls. Buddhists have long thought the owl to be an enemy of ignorance and a representation of isolation and the need for deep meditation. In Athens, owls represented a force of mystery, but one associated with good. The owl was the symbol of the Greek goddess Athena, goddess of night, war, wisdom, and the liberal arts. In many ancient cultures, owning or carrying a piece of an owl as a charm was thought to provide special protection from evil spirits and health problems, such as epilepsy and rabies. Other ancient cultures believed that energy, wisdom, and bravery might be imparted to the carrier of owl charms. Different cultures used different parts of owls in their charms, including the feet, feathers, eyes, heart, bones, or even the entire owl. .