First documented record of the Silvery-cheeked Antshrike Sakesphorus cristatus ( Wied-Neuwied , 1831 ) ( Passeriformes : Thamnophilidae ) for the state of Sergipe , Brazil

This note provides the first documented record of the Silvery-cheeked Antshrike Sakesphorus cristatus (Wied-Neuwied, 1831) for the state of Sergipe in Brazil, based on a field record and extensive search in the literature, museums, and online databases. The new record of this species presented here may contribute to the knowledge of its occurrence for future assessments of the conservation status of Brazilian birds.


Introduction
The Silvery-cheeked Antshrike Sakesphorus cristatus (Wied-Neuwied, 1831) is a small passerine bird of just 12.7 cm.This species shows sexual dimorphism.The male has a brown back, a black crest, whitish lower parts, black anterior neck, and throat.The female has an intense brown color in the crest, crown, and mantle.It also has a gray tail with light brown lower parts and flanks, and dark wings marked like males (Sick 2001).
Until recently, this thamnophilid species had its distribution limited to the Caatinga in northeast Brazil (Pinto 1978, Ridgely and Tudor 1994, Sick 2001, Zimmer and Isler 2003).In recent years, many records documented the existence of this species in the middle São Francisco River and the Espinhaço Chain region.These records, thus, shifted the southern limit of its known distribution range (Kirwan et al. 2001, Kirwan et al. 2004), including the Cerrado biome (Marini and Lopes 2005).

Methods
The new record of the Silvery-cheeked Antshrike, S. cristatus, was made during fieldwork in March 2016 in municipality of Simão Dias, in western Sergipe, which has a harsh and semi-arid climate.Information on the species distribution was found in known digitalized data-

NOTES ON GEOGRAPHIC DISTRIBUTION
bases such as the biodiversity portal (ICMBIO 2016), Species Link (CRIA 2016), and Macaulay Library (CLO 2016), as well as through a direct search in the Zoology Museum of the University of São Paulo (MZUSP) and personal communication with the Museum of Natural History of Taubaté (MHNT) and Emílio Goeldi Paraense Museum (MPEG).All records were standardized to the same coordinate system (Datum WGS84) and vectorial edition through ArcGIS 9.3 (ESRI 2009).To compare the new records to the present distribution of the species, the polygon of the species distribution from IUCN was downloaded (Bird Life International 2016), allowing a comparative analysis.

Results
A Silvery-cheeked Antshrike S. cristatus male was recorded in a typical fragment of shrub Caatinga (10.8137° S, 037.9442°W) in a matrix of cow and goat pastures of approximately 356 ha.Adjacent to the site where the S. cristatus was seen was an animal watering tank.The male was observed and photographed while perching in typical Caatinga vegetation.It was observed for several minutes and its striking physical features left no doubt about the identification of the species (Fig. 1).

Discussion
Although the IUCN polygon of the species distribution already comprises the state of Sergipe, no publication or museum database present a record of S. cristatus for this region.Data from the surveys also highlights the absence of this species in the state of Alagoas (Table 1, Fig. 2).
The species is categorized as Least Concern according to the IUCN (Bird Life International 2016), but an assessment made in 2011, during the workshop to assess the conservation status of Brazilian birds (Caatinga), categorized S. cristatus with the status of Insufficient Data because little information is known about its abundance and ecological needs.It is rare in part of its distribution range.
The current habitat fragmentation of the biomes where S. cristatus can be found suggests a possible population decline.The new record of this species presented here may contribute to the knowledge of its occurrence for future assessments of the conservation status of Brazilian birds.