Rufous-banded Owl Strix albitarsis Scientific name definitions

Endemic to the Andes, the Rufous-banded Owl is the only high elevation member of its genus. It occurs from Venezuela to Bolivia in humid montane forest from 1,700m to tree-line. It is most often detected by its deliberate series of short hoots but is rarely seen and there is thus little information on its natural history. It is primarily nocturnal, with some crepuscular activity and forages in the canopy, presumably for insects and small mammals. At low elevations, the Rufous-banded Owl will overlap with its congeners, the Black-and-white Owl (Strix nigrolineata) and Black-banded Owl (Strix huhula), both of which of are easily separated by plumage, being black and white. By vocalizations the species are best distinguished by their calls’ rhythm and emphasis on the final note.

30–35 cm (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ); 265–350 g (n = 2 specimens) (2 Chaparro-Herrera, S., S. Córdoba-Córdoba, J. P. López-Ordoñez, J. S. Restrepo-Cardona, and O. Cortes-Herrera (2017). The owls of Colombia. In Neotropical Owls: Diversity and Conservation (P. L. Enríquez, Editor), Springer International Publishing, Cham, Switzerland. pp. 317–371. Close ). Medium-sized owl with rounded head and distinctive plumage pattern. Facial disc rufous , becoming blacker around eyes, with prominent buffy-white eyebrows and lores, black chin; rest of head and upperparts blackish-brown, barred and spotted buffy-rufous; flight feathers and tail barred, primaries notched with rufous on outer web; throat white; chest dark brown, barred and spotted tawny and whitish, forming broad but rather diffuse chest band; rest of underparts with feathers edged silvery-white and with rufous-brown central area, producing large, squarish white spots that give ocellated appearance; tarsus feathered whitish; irides orange to deep yellowish-orange (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ); cere and bill yellowish-horn; toes whitish to creamy; talons pale horn with brown tips (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ). Juvenile uniformly buffy, with blackish mask, brown eyes.

The Rufous-banded Owl has 10 functional primaries (numbered distally, p1 to p10), 14 secondaries (numbered proximally, s1 to s11), including 3 tertials (numbered distally, t1 to t3). It has 12 rectrices (numbered r1 to r6, on each side of the tail). Owls are diastataxic (3 Bostwick, K. S., and M. J. Brady (2002). Phylogenetic analysis of wing feather taxis in birds: macroevolutionary patterns of genetic drift? Auk 119(4):943–954. Close ), indicating that a secondary has been lost evolutionarily between what we now term s4 and s5. See Molts for molt and plumage terminology. The following is based primarily on plumage descriptions in Marks et al. (4 Marks, J. S., R. J. Cannings, and H. Mikkola (1999). Family Strigidae (Typical Owls). In Handbook of Birds of the World Volume 5: Barn Owls to Hummingbirds (J. del Hoyo, A. Elliott, J. Sargatal, N. J. Collar, Editors). Lynx Edicions, Barcelona, Spain. pp. 76–151. Close ) and ; see Pyle (5 Pyle, P. (1997). Flight-feather molt patterns and age in North American owls. Monographs in Field Ornithology no. 2. American Birding Association, Colorado Springs, CO, USA. Close , 6 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ) for descriptions of age-determination in other Strix owls. Sexes are alike in all plumages; definitive appearance is attained at Third Basic or Fourth Basic Plumage.

Natal Down

Natal Down is present in the nest. No information for Rufous-banded Owlbut down may be tawny-buff to whitish as in other tropical Strix owls.

Juvenile (First Basic) Plumage

According to Macaulay Library images, juvenile feathering of the head and probably the underparts is buff to tawny buff, hat of the facial discs sometimes being paler buff. As in many other owls, juvenile body feathering is filamentous, rather down-like, but upperwing coverts (in this case) and flight feathers are pennaceous as in later plumages, with patterns to remiges, and rectrices as described under Formative Plumage.

Formative Plumage

Formative Plumage is like Definitive Basic Plumage, but the outer upperwing median and greater coverts (at least) are retained as juvenile feathers that are uniformly weaker and faded brown, contrasting with replaced formative upperwing lesser coverts and/or scapulars, which are fresher and darker brown. The juvenile remiges, primary coverts, and rectrices are retained and uniformly narrow, rounded, or tapered at their tips, relatively faded, and showing paler tips to the secondaries and rectrices, with little or no dark mottling (see Figures 102 and 104 in 6 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ).

Second and Third Basic Plumages

Second and possibly Third Basic Plumages appear to be identifiable in Rufous-banded Owl, being like Definitive Basic Plumage but with retained juvenile remiges. In other Strix owls, typically, one to five primaries and four to eight secondaries may be replaced during the Second Prebasic Molt, among p1 and p4–p8, the tertials, s1–s2, s5–s7, and s12–s13, contrasting with remaining retained juvenile remiges (typically among p1-p4, p8-p10, s2-s4, and s7-s10) which are worn, narrow, and faded, with paler white tips and more contrasting bars due to fading (6 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ). Following the next molt, some birds in Third Basic Plumage might be identified by retained juvenile feathers among two generations of basic feathers in the wing; 1-4 or more juvenile primaries (among p2–p4 and p9–p10) and 1-5 or more juvenile secondaries (among s3–s4 and s7–s10) being retained, very worn, and showing characteristics of juvenile feathers. It is probable that all juvenile remiges may also be replaced by completion of the Third Prebasic Molt, in which case Third and Definitive Basic Plumages are not separable. It may also be possible that more tropical species of Strix, such as Rufous-banded Owl, retain fewer feathers on average following molts than boreal species, as occurs in other widely distributed owls (5 Pyle, P. (1997). Flight-feather molt patterns and age in North American owls. Monographs in Field Ornithology no. 2. American Birding Association, Colorado Springs, CO, USA. Close ); study needed.

Definitive Basic Plumage

Crown, upperparts, and upperwing coverts dark brown with irregular and indistinct paler tawny to rufous markings or tips, the crown and nape often washed more with rufous, and some scapulars in the lateral row often with broad pale buff tips forming two short stripes or "braces" on the back. The tail is dark brown, the rectrices from above being crossed by three to seven indistinct pale grayish to buff bands, mottled with brown; ; from below the pale bands are broader and more distinct. Facial discs are tawny buff to cinnamon-rufous, mottled lightly with dark markings, and bordered with paler cinnamon to buff including whitish or pale buff supercilia that meet at the top of the bill and whitish loral feathers forming a prominet "mustache" that often connects with whitish lateral throat feathers. The primary coverts are dark brown, sometimes with obscured darker bands. The primaries and secondaries are dark brown crossed by bands of paler brown, mottled darker brown. The undersides of the remiges have broader, whiter or pale-buff bands that predominate basally. The center of the throat, sides of the neck, and upper breast is mottled dark brown, buff, and rufous-cinnamon, sometimes forming an indistinct brown collar crosses breast, which merges distinctly into paler lower underparts that are mottled or barred rufous-cinnamon and white. Underwing coverts are buff with some dark markings to the marginal lesser coverts at the bend of the wing and primary coverts with broad dark tips forming carpal marks to the underwing in flight.

Definitive Basic Plumage is distinguished from earlier plumages by having upperwing coverts and remiges that are broader and uniform in quality and coloration or showing mixed generations of lightly contrasting, basic feathers in irregular patterns (often unlike sequential patterns shown after Second Prebasic and Third Prebasic molts); outer primaries, primary coverts, and rectrices are broader, more truncate, and relatively fresher; and pale tips of feathers (especially the secondaries and rectrices) that are narrower and more heavily mottled brownish than in juvenile feathers (see Figures 102 and 104 in 6 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ).

Molt and plumage terminology follows that of Humphrey and Parkes (7 Humphrey, P. S., and K. C. Parkes (1959). An approach to the study of molts and plumages. Auk 76(1):1–31. Close ), and Howell et al. (8 Howell, S. N. G., C. Corben, P. Pyle, and D. I. Rogers (2003). The first basic problem: a review of molt and plumage homologies. Condor 105:635–653. Close ). Under this nomenclature, terminology is based on evolution of molts along ancestral lineages of birds from ecdysis (molts) of reptiles, rather than on molts relative to breeding season, location, or time of the year (see 6 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close and9 Pyle, P. (2022). Defining moults in migratory birds: a sequence-based approach. Journal of Avian Biology 2022(5):e02958. Close for more information). As in other Strix owls, Rufous-banded Owl exhibits a Complex Basic Strategy (cf. 8 Howell, S. N. G., C. Corben, P. Pyle, and D. I. Rogers (2003). The first basic problem: a review of molt and plumage homologies. Condor 105:635–653. Close , 10 Howell, S. N. G. (2010). Molt in North American Birds. Houghton Mifflin Harcourt, Boston, MA and New York, NY, USA. Close ), including a partial preformative molt and complete definitive prebasic molts, but no prealternate molts (6 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ).

Prejuvenile (First Prebasic) Molt

The Prejuvenile Molt is complete and commences in the nest and completes in the natal territory during and after fledging. There is no information on this molt in Rufous-banded Owl. In other species of Strix, natal down is replaced by downy juvenile feathers at approximately 2 to 3 weeks of age, at which time primaries erupt and begin rapid growth. The Prejuvenile Molt may be complete at about 8 to 10 weeks of age, or about 4 to 5 weeks after fledging, with the growth of outer primaries and rectrices completed last. Down may still apparent on head and thighs at age 4 mo.

Preformative Molt

The Preformative Molt is partial and includes most or all the body feathers and a few to some of the proximal upperwing secondary coverts (few if any greater coverts), but no other wing or tail feathers, as in other Strix owls (6 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ); molt of body feathers can begin at approximately 6 weeks of age, with feathers on back and scapulars appearing first, followed by abdomen, flanks, and upper breast.

Second and Third Prebasic Molts

Little information on these molts in Rufous-banded Owlbut examination of Macaulay images indicates that prebasic molts can be incomplete. In other Strix owls this molt includes most to all body feathers, some remiges, and usually all rectrices, although sometimes rectrices can be retained until the Third Prebasic Molt (11 Acker, J., and D. Garcia (2010). Notes on rectrix molt in Barred Owls (Strix varia). North American Bird Bander 35(2):61–68. Close ). Primaries appear to be consistently replaced bidirectionally from p5 or p6 and distally from p1, with the last primaries replaced being among p2–p4 and p9–p10, and secondaries are replaced bilaterally from the middle tertial and proximally from s5 and s1, with the last feathers replaced among s3–s4 and s7–s10 (5 Pyle, P. (1997). Flight-feather molt patterns and age in North American owls. Monographs in Field Ornithology no. 2. American Birding Association, Colorado Springs, CO, USA. Close , 6 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ). The Second Prebasic Molt usually includes at least the tertials, 1-5 additional secondaries among s1–s2, s5–s6, and s10–s11, and 1-5 primaries among p4–p8 and perhaps p1. The central rectrices or all rectrices can be replaced rapidly; in the former case, the tail takes on a forked or swallow-tailed look (11 Acker, J., and D. Garcia (2010). Notes on rectrix molt in Barred Owls (Strix varia). North American Bird Bander 35(2):61–68. Close ). The Third Prebasic Molt may also be incomplete, with replacement of remiges continuing where the Second Prebasic Molt arrested, in the sequence described above, and it may begin a new sequence, at least within the tertials. Some birds may replace all juvenile remiges by the completion of the Third Prebasic Molt, whereas in others at least some juvenile feathers may be retained, most typically among p2–p4, p9–p10, s3–s4, and s7–s9. It may be possible that more tropical species of Strix, such as Mottled Owl, retain fewer feathers on average following molts than boreal species, as occurs in other widely distributed owls (6 Pyle, P. (2022). Identification Guide to North American Birds. Part I, Second Edition. Slate Creek Press, Forest Knolls, CA, USA. Close ); study needed.

Definitive Prebasic Molt

The Definitive Prebasic Molt appears to be incomplete or complete, perhaps more often complete in Rufous-banded Owl than in other boreal species of Strix. It is like previous prebasic molts but, among remiges, this molt continues in sequence from termination points of the previous molt while new sequences may begin, resulting in several waves of replacement in Staffelmauser-like patterns and with 2-3 generations of basic feathers being present upon completion.

Bill and Cere

In nestlings, the bill is grayish, quickly becoming dull olive to bluish in juveniles. In Adults, the bill is dull olive to greenish yellow or yellow. The cere in adults is dull orange-yellow to mustard yellow.

Iris

At all ages the iris is dark brown or brownish black, perhaps slightly tinged cherry red in older birds.

Tarsi and Toes

The legs and feet are pale yellowish. The talons are pale horn, often with black tips.

Species name often incorrectly spelt as albitarsus. Affinities uncertain; seems not to be closely related to other members of genus. Individual variation rather marked; sometimes three subspecies are tentatively recognized but we treat the species here as monotypic (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close , 12 Mikkola, H. (2014). Owls of the World. A Photographic Guide. 2nd edition. Firefly Books, Buffalo, NY, USA. Close , 13 Enríquez, P.L. ed. (2017). Neotropical Owls: Diversity and Conservation. Springer International Publishing, Cham, Switzerland. Close ).

Andes from northern Venezuela south to western and central Bolivia.

Humid montane evergreen forest and cloudforest, including Podocarpus (14 Schmitt, C. J., D. C. Schmitt, J. Tiravanti C., F. Angulo P., I. Franke, L. M. Vallejos, L. Pollack, and C. C. Witt (2013). Avifauna of a relict Podocarpus forest in the Cachil Valley, north-west Peru. Cotinga 35:17–25. Close ), with dense understory, epiphytes and mosses, from ca. 1,700–3,700 m elevation (15 Krabbe, N., P. Flórez, G. Suárez, J. Castaño, J. D. Arango, and A. Duque (2006) The birds of Páramo de Frontino, Western Andes of Colombia. Ornitología Colombiana 4:39–50. Close , 1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ); in Venezuela, found in open areas with scattered trees between forested parts.

Presumably resident (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ).

Diet unstudied. Probably insects and small mammals. Nocturnal; active shortly after dark and before dawn. Forages in canopy and reported also to hunt from perches at forest edge (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ).

Fast series of 5–10 short, deep, guttural notes followed by brief pause and then an explosive higher-pitched note: hu hu hu hu hu, HOOa, or "hu hu hu hu hu hu hu hu hu hu, HOOa"  (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ). Rhythm different from songs of Black-banded Owl (Strix huhula) and Black-and-white Owl (Strix nigrolineata). Also utters series of gruff single hoots: “rrroo rrroo rrroo rrroo...”  (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ).

Recently fledged bird found in third week June in Colombia; juvenile seen in August in Venezuela; no other information (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ).

Not globally threatened (Least Concern). CITES II. Status uncertain; no information on global population size or population trends. Locally fairly common, but few reliable data. Has been recently recorded along the Mérida-La Azulita road and Páramo de Tamá (Venezuela), near Río Blanco (Colombia), at Pasochoa Forest Reserve and along the Nono-Mindo and Baeza-Tena roads (Ecuador). Probably adversely affected by cutting of forest habitat. Further study needed (1 König, C., F. Weick, and J.-H. Becking (2008). Owls of the World. Second Edition. Christopher Helm, London, UK. Close ).