New bird distribution records for Lambayeque , Peru : Nomonyx dominicus

The department of Lambayeque, in northwestern Peru, is primarily arid land and seasonally dry forests dominated by Acacia and Prosopis trees. Development and grazing have encroached on much of the native vegetation, leaving populations of many endemic birds confined to remaining native vegetation (e.g. Stager et al. 2012). Much of the department remains to be surveyed systematically for flora and fauna. The department was the site of the rediscovery of the presumed-extinct White-winged Guan (Penelope albipennis Taczanowski 1878) in the 1970’s (Angulo 2008). During the seasons of March-May 2011 and February-May 2012, several ornithologists employed on a project examining the Tumbes Swallow (Tachycineta stolzmanni Phillipi, 1902) surveyed little-visited areas of Lambayeque, concentrating along the old Pan-American Highway between Chiclayo and Olmos. While birdwatching groups often visit the vicinities of Olmos and Ferreñafe, no bird records exist for the majority of this department. Full records with bird abundances, effort data and observations are archived in eBird (Cornell Lab of Ornithology) and are publically accessible. From all the records made, two deserve to be extensively documented and are detailed below.

The department of Lambayeque, in northwestern Peru, is primarily arid land and seasonally dry forests dominated by Acacia and Prosopis trees.Development and grazing have encroached on much of the native vegetation, leaving populations of many endemic birds confined to remaining native vegetation (e.g.Stager et al. 2012).Much of the department remains to be surveyed systematically for flora and fauna.The department was the site of the rediscovery of the presumed-extinct White-winged Guan (Penelope albipennis Taczanowski 1878) in the 1970's (Angulo 2008).During the seasons of March-May 2011 and February-May 2012, several ornithologists employed on a project examining the Tumbes Swallow (Tachycineta stolzmanni Phillipi, 1902) surveyed little-visited areas of Lambayeque, concentrating along the old Pan-American Highway between Chiclayo and Olmos.While birdwatching groups often visit the vicinities of Olmos and Ferreñafe, no bird records exist for the majority of this department.Full records with bird abundances, effort data and observations are archived in eBird (Cornell Lab of Ornithology) and are publically accessible.From all the records made, two deserve to be extensively documented and are detailed below.
Nomonyx dominicus (Linnaeus 1766): The status of Masked Duck on the western coast of Peru is not wellknown.A handful of scattered historic records span the coast from Lima to Lambayeque, but the few recent records exist solely from the Chan-chan complex near the city of Trujillo and on ACP Bosque Natural El Cañoncillo, near Pacasmayo (Ponce and Marín Díaz 2012).Masked Ducks may have been extirpated as a breeding species on the northwestern coast (Schulenberg et al 2010).However, the species is a common wanderer, thus there exists a potential that its range is very fluid.
Abstract: New records of the Great Inca-finch (Incaspiza pulchra) and the Masked Duck (Nomonyx dominicus) from 2011 and 2012 in the department of Lambayeque, Peru are presented and discussed.Several Masked Ducks were discovered in seasonal wetlands near the town of La Viña.Single individuals (possibly the same) of the inca-finch were found in both 2011 and 2012 on Cerro Chalpón, near the city of Motupe, and frequent handouts offered by pilgrims to a shrine on the hill.Both these records represent significant range expansions or previously unrecorded populations.New bird distribution records for Lambayeque, Peru: Nomonyx dominicus (Linneaus, 1766) (Anatidae) and Incaspiza pulchra (Sclater, 1886) (Emberizidae) On April 28, 2012, EL observed an alternate-plumaged male with a presumed adult female in a small pond, approximately 20 x 10 m dominated by unidentified Juncus spp.and Salvinia spp.adjacent to La Viña reservoir (6°23′29″ S, 79°45′28″ W, 300m).Despite an hour of searching after the initial sighting from all vantage points around the pond, no further sightings were made.The following evening, four birds were noted by 4 observers after over an hour of waiting, though the fading light did not permit the plumage to be studied.On May 21 st , three birds were seen in the late morning in the same location (5 observers), including a presumed pair and another darker grayer female/immature type.On the morning of May 23 rd , in that same location an adult pair was seen again and photographed, while in another pond nearby 6 juv/ immature-type birds were also studied and photographed (Figure 1).Therefore, at minimum 8 birds were present in the area at one time.
Because at least one alternate-plumaged male was noted during both the first and last sightings, the sightings probably coincide with the breeding season of the bird in this region.We can find no references indicating marked size differences in males/females, thus we believe the noted size difference represented juveniles.Additionally, the 6 female/immature-type birds may be juveniles, though separating juvenile and adult females of the species is difficult.Additionally, if we assume a sex ratio of 1:1 (for primary and secondary sex ratios of other ducks: Bellrose et al 1961) and randomly assorted groups of adults, the chances of having six females together by chance is only 1.56%.Therefore, we believe this group contained juveniles though whether in post-natal dispersal from afar or locally we cannot say with certainty.
The reservoir adjacent to these ponds does not hold water all year, yet we have encountered nests and young Because of the rarity of this bird in Peru in general and the coast in particular and the paucity of information we have on its status, we believe these records, indicating possible breeding in suitable habitat, are important and ought to be followed up in subsequent seasons here and in other patches of suitable habitat.

Incaspiza pulchra.
A disjunct population of Great Incafinches was recently discovered outside of Trujillo, in the department of La Libertad (Nunez-Zapata and Tiravanti 2012).Previously unknown from this far north, this population expanded the known range of the species range by ~120km northward.Gonzales (2003) recorded several individuals from coastal hills near Lima, which dropped the known lower elevational limit from ca.1000 m to ca. 400 m.No analysis yet has examined plumage, morphological or vocal differences between the coastal birds and their interior counterparts.
On April 9, 2011 EL discovered and photographed a Great Inca-finch (Incaspiza pulchra) at Cerro Chalpón (06°05′09″ S, 79°44′13″ W, 580 m), outside of the city of Motupe, in Lambayeque department.On a second trip on March 13, 2012, both authors encountered one again in the same location and obtained photographs (Fig. 2) and a recording of a repeated song (Cornell Lab of Ornithology, Macaulay Library: LNS 168796).Both records occurred inside the Sanctuary of the Cross of Motupe, a Catholic landmark of peregrinations of thousands each year and both occurred in rocky areas with scattered cacti and bromeliads.The sanctuary guardian reported that the Inca-finch feeds on rice scattered by the pilgrims, though he does not see it daily.
This hill was one of the few known nesting sites of the Andean Condor (Vultur gryphus) in Lambayeque department (Wallace et al. 1983) but is badly degraded by cutting for firewood and grazing.However, the parts of the hill where we observed the Inca-finch are reasonably inaccessible except the small portion where the sanctuary lies.Whether a small population exists or these records pertain to the same individual remains to be seen.Similar hills near La Viña, Olmos, Salas, Algarrobo and Sauce were searched for the species without any success.Another very similar hill just southwest of Chalpón holds similar habitat, but we were not able to gain access to the hill to search.
This record extends the distribution of this species some 220 km NW of the known range (roughly ~210 km N), from Cerro Campana, La Libertad department (Núñez-Zapata and Tiravanti 2012).Quiet and easily overlooked,  perhaps this species is more common in coastal hills than present knowledge suggests.Additionally, further studies should examine any differences in ecology and morphology from the inland populations.These records bely the fact that even in a well-known region of Peru, frequented by birdwatching groups, small populations of birds remained unnoticed until this time.Though it is very possible that the Masked Ducks do not breed here yearly and move in during wet years, the cryptic nature of this species means it could easily escape notice even were it in areas with heavy birdwatching presence.The retiring nature of the finch and its presence in steep, sparse, rocky terrain suggests it was overlooked as well.