Foothill screech owl

Foothill screech owl
Not recognized (IUCN 3.1)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Strigidae
Genus: Megascops
Species: M. roraimae
Binomial name
Megascops roraimae
Salvin, 1897
Synonyms

Otus roraimae

The foothill screech owl (Megascops roraimae) is a species of owl in the family Strigidae. It is found in forests and dense second growth at altitudes of 200–1,800 metres (660–5,910 ft) in northern and western South America.[1][2] Its taxonomy is extremely complex and a matter of dispute (see taxonomy).

Taxonomy

All screech owls were formerly included in the genus Otus, but today they are placed in Megascops.

This species is a member of the M. guatemalae complex, which also includes the Chocó screech owl (M. centralis).[3] All are sometimes considered conspecific under the name vermiculated screech owl (M. guatemalae).[3]

When split from the Middle American screech owl, the populations in South America and southern Central America (Panama and Costa Rica) can be treated in three ways:

  1. Include all in a single species, the vermiculated screech owl (M. vermiculatus).[4]
  2. Place populations in northern Venezuela, northern Colombia, Panama and Costa Rica in the vermiculated screech owl (M. vermiculatus), populations in the Tepuis in the Roraiman screech owl (M. roraimae), populations in the lower east Andean foothills in the Rio Napo screech owl (M. napensis), and populations in the Chocó in the Chocó screech owl (M. centralis).[5]
  3. Place all in the foothill screech owl (M. roraimae), except the populations in the Chocó, which are then the Chocó screech owl (M. centralis). Costa Rica has both the foothill screech owl and the Middle American screech owl.[1][2]

As there are significant vocal differences between the various populations, and voices are of great importance in species-level taxonomy in owls, it is difficult to justify keeping them all together[5] as done in the first treatment above. There appear to be few, if any, vocal differences between populations in northern Venezuela, the Tepuis and the lower east Andean foothills, and the split between the "Middle American" song, a long trill, and the "Chocó" song, a short trill, appears to be in Costa Rica (rather than Panama, where all appear to sing the "Chocó" song).[1][2][3] This conflicts with the second treatment above, but matches the third treatment. Under this treatment the foothill screech owl (M. roraimae) includes napensis as a subspecies, and is found locally along the lower east Andean slope from Venezuela, through Colombia, Ecuador and Peru, to Bolivia, along the eastern (that is, Venezuelan) slope of the Perijá Mountains, the Venezuelan Coastal Range, and the Tepuis in southern Venezuela, far northern Brazil and Guyana.[1][2] It is replaced by the closely related Yungas screech owl (M. hoyi) in southern Bolivia and north-western Argentina,[4] and a population in the Santa Marta Mountains in Colombia may represent a new, scientifically undescribed species.[6]

Appearance

The foothill screech owl has a total length between 20 and 22 centimetres (7.9 and 8.7 in),[1][2] with a wing length of between 15 and 17.5 centimetres (5.9 and 6.9 in).[7] Its tail is typically around 8 centimetres (3.1 in) in length, and its beak is a bit more than 2 centimetres (0.79 in).[7] Its tarsus is 24–31.5 millimetres (0.94–1.24 in).[7] The plumage of the foothill screech owl is dimorphic: one morph is overall grayish-brown and the other is overall rufous.[1]

References

  1. 1 2 3 4 5 6 Hilty, S. L. (2003). Birds of Venezuela. 2nd edition. Princeton University Press. ISBN 0-691-02131-7
  2. 1 2 3 4 5 Ridgely, R. S., & Greenfield, P. J. (2001). The Birds of Ecuador. Cornell University Press. ISBN 0-7136-6116-X (vol. 1), ISBN 0-7136-6117-8 (vol. 2).
  3. 1 2 3 Robbins, M. B. (2001) Continue to recognize a broad Otus guatemalae (namely to include O. vermiculatus, O. napensis, O roraimae). South American Classification Committee. Accessed 25 January 2011.
  4. 1 2 Holt, Berkley, Deppe, Enríquez Rocha, Petersen, Rangel Salazar, Segras, & Wood (1999). Guatemalan Screech-owl (Otus guatemalae), Vermiculated Screech-owl (Otus vermiculatus) and Hoy's Screech-owl (Otus hoyi). Pp. 180-181 in: del Hoy, Elliott, & Sargatal. Eds. (1999) Handbook of the Birds of the World. Vol. 5. Barn-owls to Hummingbirds. Lynx Edicions. ISBN 84-87334-25-3
  5. 1 2 König, C., Weick, F., & Becking, J. H. (1999). Owls. Pica Press. ISBN 978-0-300-07920-3
  6. ↑ Boesman, P. (1994). Megascops guatemalae ssp. nov.. Xeno-canto. Accessed 25 January 2011.
  7. 1 2 3 Friedhelm Weick (2006). Owls (Strigiformes): Annotated and Illustrated Checklist. Springer. ISBN 3-540-35234-1.
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