Tropical Screech Owl (Megascops choliba)

Tropical Screech Owl

[order] STRIGIFORMES | [family] Strigidae | [latin] Megascops choliba | [authority] Vieillot, 1817 | [UK] Tropical Screech Owl | [FR] Petit duc choliba | [DE] Cholibaeule | [ES] Autillo Choliba | [NL] Choliba-schreuwuil

Subspecies

Monotypic species

Genus

The genus Megascops comprises 22 living species are known at present, but new ones are frequently recognized and unknown ones are still being discovered on a regular basis, especially in the Andes. For most of the 20th century, this genus was merged with the Old World scops-owls in Otus, but nowadays it is again considered separate based on a range of behavioral, biogeographical, morphological and DNA sequence data. Screech-owls are restricted to the Americas. Some species formerly placed with them are nowadays considered more distinct.
As usual for owls, female screech-owls are usually larger and fatter than the males of their species, with owls of both sexes being compact in size, shape, and height. The Eastern Screech-owl Megascops asio is one of the smallest species of owls in North America. All of the birds in this genus are small and agile. Screech-owls are generally colored in various brownish hues with usually a whitish, patterned underside, which helps to camouflage them against the bark of trees. Some are polymorphic, occurring in a grayish- and a reddish-brown morph.

Physical charateristics

A relatively small screech owl with short ear tufts that are raised mostly during daytime. There are grey-brown, brown and rufous morphs, with intermediates. Most are of the grey-brown morph. This owl has a yellow iris and a light grey facial disk, with a prominent black border; underparts white with a herring-bone pattern where each feather has black shaft streaks throughout. Crown and upperparts heavily streaked dark; tail and flight-feathers are barred with brown and light buff, the scapulars have a dark-edged pale spots, what give them a white line along each side above the wing. The bill is greenish-grey, feathered tarsus, toes are bare and feet are grey-brown.

Listen to the sound of Tropical Screech Owl

[audio:http://www.planetofbirds.com/MASTER/STRIGIFORMES/Strigidae/sounds/Tropical Screech Owl.mp3]

Copyright remark: Most sounds derived from xeno-canto


wingspan min.: 14 cm wingspan max.: 18 cm
size min.: 20 cm size max.: 24 cm
incubation min.: 0 days incubation max.: 0 days
fledging min.: 30 days fledging max.: 0 days
broods: 1   eggs min.: 1  
      eggs max.: 4  

Range

Latin America : Costa Rica to Northeast Argentina

Habitat

This species is found in a wide variety of habitats. However, Tropical Screech owls occur mostly in semi-open habitats, like timbered savannah, semi-open areas with scattered trees, forest edges, second-growth forests, plantations, and also town parks. In a gradient of physiognomies from open to woody areas, as the Brazilian savannah, this owl seems to avoid pure grasslands or grassland savannahs with shrubs, preferring patches with at last some trees to woody savannahs. Generally they occur in areas from sea level to 1500m, but they have also been recorded at 3000m. This raptor is almost strictly nocturnal, initiating its activities at dusk

Reproduction

These owls lay eggs in January – July in Northern Hemisphere; in Southern Hemisphere, the egg laying was recorded in September-October. But males normally sing on August, initiating the courtship period, when both sexes are vocally active. These owls nest in cavities, as natural or old woodpecker holes in trees, but also in termite mounts and nest boxes. Usually about 1-4 white eggs, averaging 34.3 x 29.3mm, are laid on the bottom of cavity without any protection. Incubation is provided by female. In Misiones (Argentina) a male was reported carrying food to the nest. The nestlings are brooded for about a month when the young owls fledge.

Feeding habits

Food habits are poorly known. Few samples of pellets and field observations suggest a mostly insectivorous diet, including crickets, katydids, beetles, ants, spiders and scorpions. Preys are mostly nocturnal and live on the ground. Insects can be captured on wing or on the ground. There are observations of individuals catching insects in flight, particularly in the vicinity of artificial light sources, suggesting a learning process. Small vertebrates are also consumed as rodents, opossums, anurans and snakes, but in small proportions. However, in terms of estimated prey biomass consumption, these vertebrates can support 1/3 to 1/2 of the diet.

Video Tropical Screech Owl

httpv://www.youtube.com/watch?v=vQimnai3y1I

copyright: youtube


Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The Tropical Screech owl is distributed on most of South America east of the Andes from Costa Rica to northern Argentina, east of Ecuador, Colombia, Peru and Bolivia, and all over Venezuela, Guyana, Suriname, French Guiana, Brazil, Paraguay and Uruguay. It was also reported in Trinidad .
Tropical Screech Owl status Least Concern

Migration

These owls are probably resident, but little is know about their movements.

Distribution map

Tropical Screech Owl distribution range map

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