Family Typical Owls (Strigidae)

Least Concern

Unspotted Saw-whet Owl (Aegolius ridgwayi)


Taxonomy

French: Nyctale immaculée German: Ridgwaykauz Spanish: Mochuelo moreno
Other common names: Southern Saw-whet Owl
Taxonomy:

Cryptoglaux ridgwayi

Alfaro

, 1905,

Cerro de la Candelaria, near Escazú, Costa Rica

.

Probably closest to A. acadicus, and perhaps conspecific, with apparent hybridization where ranges appear to overlap (in S Mexico); further study needed. Validity of races uncertain#R: it is suggested that both tacanensis and rostratus represent hybrids between present species and A. acadicus; research required. Three subspecies provisionally recognized.

Subspecies and Distribution
  • A. r. tacanensis R. T. Moore, 1947 – S Mexico (Chiapas).
  • A. r. rostratus (Griscom, 1930) – Guatemala; presumably this race in El Salvador.
  • A. r. ridgwayi (Alfaro, 1905) – Costa Rica and W Panama.
  • Descriptive notes

    18–20 cm; c. 80 g. Small (wing length 133–146 mm; tail c. 64 mm), large-headed and variable in colour. Plumage recalls juvenile A. acadicus: facial disc... read more

    Voice

    Male song a series of whistled “hoo hoo hoo hoo hoo” toot notes; very similar to... read more

    Habitat

    Humid pine-oak and oak forest of highlands and cloudforest; sometimes in edges and gaps with... read more

    Food and feeding

    Probably mainly small mammals, such as rodents and shrews (Sorici­dae), also bats, and small birds; presumably insects, too;... read more

    Breeding

    Little known. Clutches of 5–6 eggs found in Mar; most nests probably in old woodpecker hole.

    Movements

    Resident, but little known.

    Status and conservation

    Not globally threatened (Least Concern). CITES II. Formerly considered Near Threatened. Generally considered uncommon, with global population estimated at fewer than 50,000... read more

    Recommended citation

    Holt, D.W., Berkley, R., Deppe, C., Enríquez Rocha, P., Petersen, J.L., Rangel Salazar, J.L., Segars, K.P., Wood, K.L. & Marks, J.S. (2019). Unspotted Saw-whet Owl (Aegolius ridgwayi). 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. (retrieved from https://www.hbw.com/node/55097 on 14 December 2019).