Шығыс сұрғыл бүркіттің түрлері мен сипаттамалары

Species of owl

The eastern screech owl (Megascops asio) or eastern screech owl, is a small owl that is relatively common in Eastern North America, from Mexico to Canada. Linnaeus based his account on the "little owl" that had been described and illustrated by the English naturalist Mark Catesby in his book The Natural History of Carolina, Florida and the Bahama Islands. The specific epithet is the Latin word for a type of eared owl. The eastern screech owl is now one of 22 screech owls placed in the genus Megascops that was introduced in 1848 by the German naturalist Johann Kaup. Five subspecies are typically recognised for the eastern screech owl, but the taxonomy in the species is considered "muddled". Much of the variation may be considered clinal, as predictably, the size tends to decrease from north to south and much of the color variation is explainable by adaptation to habitat. M. a. asio (Linnaeus, 1758) includes previously described races no longer considered valid such as M. a. carolinensis, M. a. naevius and M. a. striatus. It is resident from eastern Minnesota to southwestern Quebec and southern New Hampshire south to Missouri, Tennessee, and northern South Carolina. Dorsal color is cold gray; the red morph is common (about 39% of overall population). M. a. hasbroucki (Ridgway, 1914). Replacement name for the formerly described M. a. trichopsis. This subspecies is a resident from Oklahoma panhandle and southern Kansas south to Edwards Plateau of central Texas. This subspecies is also similar to M. a. asio but the dorsal color is buffy gray, the red morph being rare (~5% of population), and markings coarse and dense. This race averages at a similar size as the first two, at in wing chord length. M. a. mccallii (Cassin, 1854) includes previously described races such as M. a. enano and M. a. semplei. Resident from southern Texas (Big Bend to lower Rio Grande Valley) and northwestern Chihuahua and northern Coahuila southeast to eastern San Luis Potosí, this race is similar to M. a. hasbroucki, but its markings are fine and dense so the dorsum looks heavily mottled, with red morphs being rare (apparently entirely absent in South Texas). Its body size is smaller to the northern races, with a wing chord length of Unlike other subspecies, the primary song of M. a. mccallii lacks a terminal whinny. M. a. floridanus (Ridgway, 1873) is resident in Florida and southern Georgia west through Gulf Coast states to western Louisiana and north in the Mississippi River valley to southeastern Arkansas. This race's dorsal color is often rusty brown (red morph equally common), with fine and dense markings. As described above, this subspecies may occur in a true "brown morph". It is the smallest race of eastern screech owl, ranging in wing chord length from .

Adults range from in length and weigh
Two color variations are referred to as "red or rufous morphs" and "gray morphs" by bird watchers and ornithologists. Rusty birds are more common in the southern parts of the range; pairings of the two color variants do occur. While the gray morph provides remarkably effective camouflage amongst the bark of hardwood trees, red morphs may find security in certain pine trees and the colorful leaves of changing deciduous trees. The highest percentage of red morphs is known from Tennessee (79% of population) and Illinois (78% of population). A rarer "brown morph" is known, recorded exclusively in the south (i. e. Florida), which may be the occasional product of hybridation between the morphs. In Florida, brown morphs are typically reported in the more humid portions of the state, whereas they appear to be generally absent in the northern and northwestern parts of the state. A paler gray variation (sometimes bordering on a washed out, whitish look) also exists in western Canada and the north central United States. Evidence of higher metabolic rates was shown by a higher proportion of gray morphs in the rural areas surrounding Waco, TX compared to the warmer suburban areas. Rufous screech owls also had higher mortality during cold winters.

Their breeding habitat is deciduous or mixed woods in eastern North America. Usually solitary, they nest in a tree cavity, either natural or excavated by a woodpecker. Holes must have a entrance to accommodate this owl. Usually, they fit only in the holes excavated by northern flickers (Colaptes auratus) or pileated woodpeckers (Dryocopus pileatus), as apparently the midsized red bellied woodpecker (Melanerpes carolinensis) make holes that are not large enough to accommodate them. In terms of ecological niche, they have no easy ecological equivalent in Europe, perhaps the closest being the little owl (Athene noctua), the similar looking Eurasian scops owl (Otus scops) being smaller and weaker and the long eared owl (Asio otus) more fully dependent on rodents. The success of eastern screech (and western screech) owls in North America may be the reason long eared owls are much more restricted to limited northern forest habitat in North America than they are in Europe. and cicadas, although they likely consume any commonly available flying insect. Also taken are crayfish, snails, spiders, earthworms, scorpions, leeches, millipedes, and centipedes. Small mammals, ranging in size from shrews to young rabbits (Sylvilagus ssp. ), are regular prey and almost always become the owl's primary food during winter. Small rodents such as microtine rodents and mice account for about 67% of mammals taken, although rodents of a similar weight to the owl, such as rats and squirrels, especially the red squirrel (Tamiasciurus hudsonicus), are also taken. Jumping mice (Zapus ssp. ), chipmunks, moles, and bats (especially the little brown bat (Myotis lucifugus) may be taken occasionally. Small birds such as chickadees (Poecile ssp. ), swallows, sparrows, finches, flycatchers, and warblers are the most common avian prey, and such species are normally caught directly from their nocturnal perches or during nocturnal migration. In Ohio, the most commonly reported avian prey species, and most commonly stored food items behind meadow voles, were yellow rumped warblers (Setophaga coronata) and white throated sparrows (Zonotrichus albicollis). Climate, food sources, and predator presence are some potential factors that impact the behaviors of suburban and rural eastern screech owls. Living in suburbia can have some additional impacts on eastern screech owl behavior such as secondary poisoning, vehicles, and more predation and competition from raccoon, opossum and squirrels. found that there were larger average brood sizes and earlier average fledging dates of eastern screech owls shown in moderate and high density suburban areas than in low density suburban and rural areas. There are various differences in habitat that have impacts on the nesting behaviors of eastern screech owls. Eastern screech owl feeding behaviors have also been shown through previous research to be impacted by whether the owl lived in a rural or suburban area. In a previous study, prey diversity for eastern screech owls peaked in low density suburban areas. A previous study showed that as suburban climates got warmer over the course of a few years, eastern screech owls started nesting an average of 4.5 days earlier annually.