New distribution records of the Buff-fronted Owl Aegolius harrisii Cassin , 1849 ( Aves : Strigidae ) in Peru

We review the distribution of the Buff-fronted Owl Aegolius harrisii harrisii in Peru, supported by unpublished museum records and new specimens and observations. Compared to previous published records, the distribution and elevation range for the species in Peru are expanded significantly. Based on all records, we deduce that the overall distribution of A. harrisii in Peru is almost continuous, from the northwestern Andes to the eastern southern Andes, between 250 and 2960 m. The northern Peruvian Andes show a dense distribution of A. harrisii records compared to the distribution elsewhere in the Andes. Centro de Ornitología y Biodiversidad (CORBIDI), Calle Santa Rita 105, oficina 202, Urbanización Huertos de San Antonio, Lima 33, Peru. * Corresponding author: javbar@corbidi.org Antonio García Bravo and Javier Barrio * New distribution records of the Buff-fronted Owl Aegolius harrisii Cassin, 1849 (Aves: Strigidae) in Peru The Buff-fronted Owl Aegolius harrisii (Cassin, 1849) is a rare and local species that frequently passes unnoticed. A small owl (19–23cm), it is identified by the buff face crossed by a blackish “Y” over the eyes and the bill, the buff underside without marks, and brown wings with white spots (Figure 1; Meyer de Schauensee 1966; Hilty and Brown 1986; Fjeldså and Krabbe 1990; Marks et al. 1999; König et al. 1999; Ridgely and Greenfield 2001; Hilty 2003; Schulenberg et al. 2010). Aegolius harrisii is distributed throughout much of South America (Fjeldså and Krabbe 1990). Other than a reportedly continuous distribution from southeast Brazil to Paraguay and northeast Argentina, its distribution includes numerous scattered localities in northern and western South America (Fjeldså and Krabbe 1990). Presently, three subspecies are recognized within A. harrisii: 1) A. h. harrisii (Cassin, 1849), of the Andes from northwestern Venezuela south to central Peru and the taxon treated in this article; 2) A. h. iheringi (Sharpe, 1899), of eastern Bolivia, Paraguay, eastern and central Brazil, south to northeastern Argentina and northeastern Uruguay; and 3) A. h. dabbenei (Olrog, 1979), in northwest Argentina. The validity of the three subspecies is doubted by Girão and Albano (2010). The elevation range reported for A. harrisii is 600 to 3800 m (Meyer de Schauensee 1966; Hilty and Brown 1986; Fjeldså and Krabbe 1990; Marks et al. 1999; König et al. 1999; Ridgely and Greenfield 2001; Hilty 2003). However, in Brazil, the species has been reported to as low as 50 m (Negret et al.1984). Throughout its range, the species inhabits very different habitat types and climates: e.g., tropical rainforest, montane semi-humid forests, palm plantations, Podocarpus forests, Polylepis forests, chaco, caatinga, central Brazil cerrado, and Tumbesian dry forest, even in urban areas (Negret et al. 1984; Fjeldså and Krabbe 1990; Studer and Teixeira 1994; Marks et al. 1999;


in Peru
The Buff-fronted Owl Aegolius harrisii (Cassin, 1849) is a rare and local species that frequently passes unnoticed.A small owl (19-23cm), it is identified by the buff face crossed by a blackish "Y" over the eyes and the bill, the buff underside without marks, and brown wings with white spots (Figure 1; Meyer de Schauensee 1966; Hilty and Brown 1986;Fjeldså and Krabbe 1990;Marks et al. 1999;König et al. 1999;Ridgely and Greenfield 2001;Hilty 2003;Schulenberg et al. 2010).Aegolius harrisii is distributed throughout much of South America (Fjeldså and Krabbe 1990).Other than a reportedly continuous distribution from southeast Brazil to Paraguay and northeast Argentina, its distribution includes numerous scattered localities in northern and western South America (Fjeldså and Krabbe 1990).
Presently, three subspecies are recognized within A. harrisii: 1) A. h.harrisii (Cassin, 1849), of the Andes from northwestern Venezuela south to central Peru and the taxon treated in this article; 2) A. h.iheringi (Sharpe, 1899), of eastern Bolivia, Paraguay, eastern and central Brazil, south to northeastern Argentina and northeastern Uruguay; and 3) A. h.dabbenei (Olrog, 1979), in northwest Argentina.The validity of the three subspecies is doubted by Girão and Albano (2010).
In this article, we cover the distribution of the subspecies Aegolius harrisii harrisii in Peru and compare it to what is known in other parts of the Andes.According to Schulenberg et al. (2010), in Peru Aegolius h.harrisii occurs in three separate areas (green dots in Figure 2), between 1500 and 2900 m, mainly in the east slope of the Andes, with some records west of the Andes in the Tumbes and Piura departments.However, our new records of the species, and a more updated revision of museum specimens, show a more widespread distribution of the species in Peru, particularly in the central and southern portions of the country.
We obtained information of six unpublished records from scientific collections, one unpublished recording of the species from Xeno-Canto (http://www.xeno-canto.Additionally, there is one record (Irma Franke, unpublished data) from Las Carpas, high part of the Zaña valley, Cajamarca department.We include this record despite there is no voucher, and her report only mentioned the locality, but no explanation was given on the type of record (observed, heard or mistnetted), the date the individual was recorded, coordinates or altitude.We mapped it in the location mentioned above, and is depicted as number 11.Previous records of Aegolius h.harrisii in Peru were restricted to seven localities, five of which were in the departments of Tumbes and Piura, northern Peru.As a result, Schulenberg et al. (2010) considered the species local and rare.In this article we present thirteen records for the species not included in the map in Schulenberg et al. (2010).Based on this new information, Aegolius h.harrisii appears to have a more extensive distribution on both sides of the Andes.Of the new records presented here, four include the western slope of the Andes in the departments of Piura, Lambayeque and Cajamarca.Two new records are located on the east slope in northern Cajamarca, three records are restricted to the southern portion of the Amazonas department, and the remaining four are single reports from each of the following departments: Junin/ Pasco, Ayacucho, Cuzco and Puno.These last three records significantly increase the species' distribution in Peru.Additionally, the elevation range for Aegolius h.harrisii in Peru is from 250 m (El Tocto) to 2960 m (Cerro Chinguela).The lowest elevation was of an individual encountered in May 1987 (as described above), after strong El Niño southern oscillation rains in northwest Peru (Marcharé and Ortlieb 1993).The subsequent change in vegetation structure and composition may have influenced the species' use of lower elevations in the area.
Based on the distribution of Aegolius h.harrisii in other parts of northern and western South America (von Sneidern 1954;Fitzpatrick and Willard 1982;Hilty 2003;Córdoba and Ahumada 2005;BirdLife International 2011), and from recordings at Xeno-Canto (http://www.xeno-canto.org),(S.Mayer: XC 1645, C. Vogt: XC 33951, N. Athanas: XC 35420, and N. Krabbe: XC 45852, 45994-45996, 45998, 46000, 46001, 46005, 46007-46014), we expect a less fragmented distribution along both sides of the Andes from Venezuela to north Peru, south along the eastern slope of the central and southern Andes of Peru, to the Amazonian slope of the Andes in Bolivia.The absence of additional distributional records through the humid forests of the central and southern Peruvian Andes can be related to the species' low natural density, nocturnal habits, small size, and soft and few calls (Barrionuevo et al. 2008;Girão and Albano 2010), combined with the low number of scientific expeditions conducted in humid montane forests in Peru.However, the sparse distribution is similar to that noted for the species elsewhere through the Andes (Hilty and Brown 1986;Fjeldså and Krabbe 1990;Marks et al. 1999;König et al. 1999;Ridgely and Greenfield 2001;Hilty 2003).An exception to this, probably explained by increased sampling efforts, is the northern Peruvian Andes.In recent years the northern forests of the Peruvian Andes have been subject to at least four ornithological expeditions and hence the greater number of records of Aegolius h.harrisii in that area.The other recognized subspecies seem to present a higher density (Marks et al. 1999;BirdLife International 2012), but their continuous mapping in various publications may be an overstatement of the abundance of the species, and probably, it is equally as sparsely-distributed elsewhere as Aegolius h.harrisii (Dan Lane, personal communication).However, its distribution depicted as few dots in a map might also be an understatement, following the natural inconspicuousness of the species (Girão and Albano 2010).

Figure 2 .Figure 4 .
Figure 2. Distribution map of Aegolius harrisii in Peru.Green dots are localities upon which the map of Schulenberg et al. (2010) was made, yellow dots indicate published records not included in Schulenberg et al. (2010), red dots with white borders indicate new records (present work).Numbers refer to numbered localities in the text.