Short-eared Owl (Asio flammeus)

Short-eared Owl

Description

The short-eared owl (Asio flammeus) is a widespread grassland species in the family Strigidae. Owls belonging to genus Asio are known as the eared owls, as they have tufts of feathers resembling mammalian ears. These "ear" tufts may or may not be visible. The short-eared owl will display its tufts when in a defensive pose, although its very short tufts are usually not visible. The short-eared owl is found in open country and grasslands. The short-eared owl is a medium-sized owl measuring 34–43 cm (13–17 in) in length and weighing 206–475 g (7.3–16.8 oz). It has large eyes, a big head, a short neck, and broad wings. Its bill is short, strong, hooked and black. Its plumage is mottled tawny to brown with a barred tail and wings. The upper breast is significantly streaked. Its flight is characteristically floppy due to its irregular wingbeats. The short-eared owl may also be described as "moth or bat-like" in flight.[10] Wingspans range from 85 to 110 cm (33 to 43 in).[11] Females are slightly larger than males. The yellow-orange eyes of A. flammeus are exaggerated by black rings encircling each eye, giving the appearance of them wearing mascara, and large, whitish disks of plumage surrounding the eyes like a mask.

Distribution And Habitat

The Short-eared Owl has a worldwide distribution. In the Caribbean, it is a common resident on Cuba and Hispaniola, and uncommon on Puerto Rico (Raffaele and others 1998). It occurs in Puerto Ricos mainland (Biaggi 1997, Oberle 2018, Raffaele 1989a) and Vieques, in the latter being an extremely rare resident (Gemmill 2015). In Puerto Rico, it can be regularly seen in the municipality of Salinas and the Caño Tiburones Natural Reserve (Oberle 2018). Nonetheless, it has also been observed in Cerro de las Mesas in Mayagüez (Biaggi 1997). The owl is a species of open habitats including open fields, pastures, short-grass marshes (Oberle 2018), rice fields, and citrus plantations (Oberle 2018, Raffaele and others 1998). The atlas fieldwork yielded a total of 51 records within 41 hexagons or 9 percent of the 479 total hexagons (see map). Of the 41 hexagons where this species was found, breeding met the atlas definition of probable in 12 percent (5) and possible in 85 percent (35), while the species was observed in 2 percent (1) of the hexagons but without evidence of breeding (see map).Short-eared Owl distribution. The map shows the highest breeding code by hexagon and overlaying the ecological life zones in Puerto Rico. Note: percentages may not total 100 due to rounding. 177Short-eared Owl/Múcaro Real

Breeding Habits

The Short-eared Owl makes a scrape nest on the ground under a bush or a thick clump of grass (Raffaele and others 1998). Previously published reports indicate that breeding occurs mostly from April to June, but some nesting activity has been noted as early as December (Raffaele and others 1998). Nevertheless, atlas results suggest that this species breeding season extends mostly from February to June and to a lesser extent from August to October and December, and peaks in March (see chart). Results suggest that this species breeds mostly within the subtropical dry forest life zone (50 percent of the hexagons) (see table and map). However, results indicate that it may also breed within the subtropical moist forest life zone (43 percent of the hexagons) and rarely in the subtropical wet forest life zone at higher elevations (8 percent of the hexagons) (see table).

Conservation

The current population trend of the Short-eared Owl is described as decreasing in North America (Butcher and Niven 2007), and it is currently listed as a species of least concern by the IUCN (BirdLife International 2016). Locally, this species is not listed in any of the threatened categories of PRDNER and USFWS. In Puerto Rico, the Short-eared Owl has a protected habitat of 15 percent or 148 km2 of the total area covered by the hexagons where evidence of breeding was found for this species (958 km2).