Long-eared owl

The long-eared owl (Asio otus), also known as the northern long-eared owlOlsen, P. D. & Marks, J. S. (2019). Northern Long-eared Owl (Asio otus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D. A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. or informally as the lesser horned owl or cat owl, is a medium-sized typical owl with an extensive range. The genus name, Asio, is Latin for "horned owl", and the specific epithet, otus, is derived from Greek and refers to a small eared owl. It breeds in Europe and the Palearctic, as well as in North America.Owls of the World: A Photographic Guide by Mikkola, H. Firefly Books (2012),

This owl prefers semi-open habitats, particularly woodland edge, as they to roost and nest within dense stands of wood but prefer to hunt over open ground.Johnsgard, P. A. (1988). North American owls: biology and natural history. Smithsonian Institution. The long-eared owl primarily hunts small rodents, especially voles, but during population cycles of their regular prey, or in arid, insular, or urbanized habitats, it takes diverse prey including birds and insects.Kiat, Y., Perlman, G., Balaban, A., Leshem, Y., Izhaki, I., & Charter, M. (2008). Feeding specialization of urban Long-eared Owls, Asio otus (Linnaeus, 1758), in Jerusalem, Israel. Zoology in the Middle East, 43(1), 49-54.Trujillo, O., Díaz, G., & Moreno, M. (1989). Alimentación del búho chico (Asio otus canariensis) en Gran Canaria (Islas Canarias). Ardeola, 36(2), 193-231.Village, A. (1981). The diet and breeding of Long-eared Owls in relation to vole numbers. Bird Study, 28(3), 214-224. The long-eared owl utilizes nests built by other animals, in particular by corvids.Marks, J. S. (1986). Nest-site characteristics and reproductive success of Long-eared Owls in southwestern Idaho. The Wilson Bulletin, 547-560.Glue, D. E. (1977). Breeding biology of Long-eared Owls. British Birds, 70(8), 318-331. Breeding success in this species is correlated with prey populations and predation risks. Unlike many owls, long-eared owls are not strongly territorial or sedentary. They are partially migratory or nomadic.Houston, C. S. (1997). Banding of Asio owls in south-central Saskatchewan. In In: Duncan, James R.; Johnson, David H.; Nicholls, Thomas H., eds. Biology and conservation of owls of the Northern Hemisphere: 2nd International symposium. Gen. Tech. Rep. NC-190. St. Paul, MN: US Dept. of Agriculture, Forest Service, North Central Forest Experiment Station. 237-242. (Vol. 190). Another characteristic of this species is its partiality for regular roosts shared by a number of long-eared owls at once.Pirovano, A., Rubolini, D., & de Michelis, S. (2000). Winter roost occupancy and behaviour at evening departure of urban long‐eared owls. Italian Journal of Zoology, 67(1), 63-66.Bosakowski, T. (1984). Roost selection and behavior of the Long-eared Owl (Asio otus) wintering in New Jersey. Raptor Res, 18(13), 7-142. The long-eared owl is one of the most widely distributed and most numerous owl species in the world, and due to its very broad range and numbers it is considered a least concern species by the IUCN. Nonetheless, strong declines have been detected for this owl in several parts of its range.Kirk, D. A., & Hyslop, C. (1998). Population status and recent trends in Canadian raptors: a review. Biological Conservation, 83(1), 91-118.

Taxonomy The long-eared owl was described by Linnaeus in 1758 in the tenth edition of Systema Naturae under the binomial name Strix otus. It is now assigned to the genus Asio that was introduced by Mathurin Jacques Brisson in 1760.

There are eight known species worldwide in the genus Asio, also referred to as eared owls.Wink, M., El-Sayed, A. A., Sauer-Gürth, H., & Gonzalez, J. (2009). Molecular phylogeny of owls (Strigiformes) inferred from DNA sequences of the mitochondrial cytochrome b and the nuclear RAG-1 gene. Ardea, 97(4), 581-592. Despite similarities and being considered as in the same genus, it was found in a study utilizing electrophoresis that the genetic distance between long-eared owls and short-eared owls was unusually large for species within the same genera.Randi, E., Fusco, G., Lorenzini, R., & Spina, F. (1991). Allozyme divergence and phylogenetic relationships within the Strigiformes. The Condor, 93(2), 295-301. Notwithstanding fossil records of Asio species showing their presence during prehistory in locations like Kansas and Idaho (Asio brevipes) and California (Asio priscus), the exact area of evolutionary origin of the long-eared owl is unknown and unlikely to ever be known.Ford, N. L., & Murray, B. G. (1967). Fossil owls from the Hagerman local fauna (Upper Pliocene) of Idaho. The Auk, 84(1), 115-117. At least three modern species represent related derivations, possibly with long-eared owls as the paraspecies or as part of a species complex that potentially bears a basal common ancestor. In all three cases, the related owls are obviously more tropical in distribution and adapted to more humid conditions, with darker plumage, and larger bodies with apparently stronger feet and more overdeveloped talons, possibly exploiting a relatively unoccupied ecological niche against competing owls. One of these three is the Stygian owl, which is the darkest derivation of all and readily known to be distinct for some time. The other two slightly larger, tropical species, possibly housed in a species complex with the long-eared owl, were at one time considered to be part of the long-eared owl species. One of these is the Madagascar owl (Asio madagascariensis), obviously endemic to the island of its name, while the other is the Abyssinian owl (Asio abyssinicus), native to east Africa, especially in the northern area such as Ethiopia.Mayr, E., & Short, L. L. (1970). Species taxa of North American birds: a contribution to comparative systematics. Nuttall Ornithological Club.Voous, K. H. (1966). The distribution of owls in Africa in relation to general zoogeographical problems. Ostrich, 37(sup1), 499-506.Snow, D. W. (1978). The nest as a factor determining clutch-size in tropical birds. Journal für Ornithologie, 119(2), 227-230. While the marsh owl of Africa is outwardly very similar to and likely closely related to the short-eared owl, the striped owl (Asio clamator) is somewhat of an outlier among living Asio species and of mysterious origin. Despite being genetically related to the other living Asio species, it does not appear to be a close cousin. Studies of the mitochondrial genome found that the Asio genus, and consequently the long-eared owl, diverged most recently among living owl groups from the Otus or scops owl genus, with a more distant branch division from the Strix genus.Lee, M. Y., Lee, S. M., Jeon, H. S., Lee, S. H., Park, J. Y., & An, J. (2018). Complete mitochondrial genome of the Northern Long-eared Owl (Asio otus Linnaeus, 1758) determined using next-generation sequencing. Mitochondrial DNA Part B, 3(2), 494-495. A study of the genetic homogeny of long-eared owls in a single roost site was shown to be slightly higher than between different roosts. However, this homogeny is relatively low for a communal roosting bird in general.Galeotti, P., Pilastro, A., Tavecchia, G., Bonetti, A., & Congiu, L. (1997). Genetic similarity in long‐eared owl communal winter roosts: a DNA fingerprinting study. Molecular Ecology, 6(5), 429-435.

Subspecies Four subspecies of the long-eared owl are recognised:

A. o. otus (Linnaeus, 1758) – This is the nominate subspecies and is distributed throughout the species' range in the Palearctic. It may be found as far west as the Azores, northwestern Africa, the Iberian Peninsula and the British Isles through as far east as Sakhalin, Japan and northern China. Some populations of this race may winter as far south as Egypt, Pakistan, northern India and southern China. The wing chord of the nominate subspecies ranges between and the tail length may be between . Size appears to increase slightly from west to east, with owls in China being about 4% larger winged than those from Europe. Despite there being no known published weights for eastern/Chinese long-eared owls, they appear to obtain the largest sizes within the species. In this subspecies, the facial disc tends to be pale ochraceous tawny, rimmed black with relatively short eyebrows that are marked whitish or absent entirely of markings. The erectile ear-tufts are prominent, being colored mainly blackish-brown with tawny edges. The upperparts are ochraceous-tawny, finely peppered with dusky spots and blackish streaks on a grey "veil", while the crown is finely mottled to dusky. The nape and hindneck bear dusky shaft-streaks with the feather outer webs of the scapulars being whitish, forming a row across the shoulder. Primaries basally are uniformly ochraceous-tawny, distally barred light and dark, while the secondaries are barred ochraceous and dusky. The tail is typically tawny with a greyish wash, overlaid with 6-8 very narrow dark brown bars. The underparts have a base colour of ochre, with the foreneck and upper breast marked with blackish-brown streaks; these become paler below and marked with dusky shaft-streaks and narrow cross-bars. The underwing has distinctive barring and dark comma-like markings at the wrist (conspicuously lacking on overlapping Eurasian short-eared owls). The eyes tend to be yellowish-orange to orange, but occasionally may be chrome yellow. The cere is brownish-flesh, the bill is grey and the talons are blackish-grey. In this subspecies, the downy chick is whitish with pink skin, while the mesoptile plumage is fluffy greyish to brownish-white with diffusely barred dusky flight and tail feathers, being similar to adults but with the ear-tufts not yet developed. A. o. canariensis (Madarász, 1901) – This subspecies is endemic to the Canary Islands. With a wing chord measurement of , this is seemingly the smallest subspecies of the long-eared owl. This race averages darker than most long-eared owls of the nominate subspecies, bearing heavier and sharper dark markings overall. Furthermore, the Canary Island long-eared owls tend to have brighter reddish-orange eyes.Baez, M. (1992). Zoogeography and evolution of the avifauna of the Canary Islands. Natural History Museum of Los Angeles County Science Series, 36, 425-431. A. o. wilsonianus (Lesson, 1830) – This subspecies is found in south-central and southeastern Canada (Manitoba to Nova Scotia) to southern USA (north Oklahoma and Virginia). The wing chord typically measures . In general, American long-eared owls are more vividly marked than many Eurasian populations. The facial disc is bright rufous, with a strong blackish rim and extensive white about the disc. The eyes are typically a deep yellow. Meanwhile, the markings on the underside usually are quite blackish and prominent with distinct cross-bars. A. o. tuftsi Godfrey, 1948 – The range is from western Canada (southern Yukon to southwest Manitoba) to south-central USA (west Texas). It differs from A. o. wilsonianus in having paler plumage. The brown mottling on upper parts is paler and more restricted. Although 1947 is printed on the title page, the article was not published until 1948. It is weakly differentiated and may comprise clinal variations due to region and habitat, rather than subspecific differences.

Description

This species is a slim and long winged owl with erectile ear tufts, which are positioned closer to the center of the head than in many other types of owl. Ear tufts, present in about half of living owls, are conjectured to be a means of intraspecies communication of intent and mood.Steinbach, G. (1980). Die Welt der Eulen. Hoffmann u. Campe.