First records of the Wing-barred Seedeater , Sporophila americana ( Gmelin , 1789 ) ( Thraupidae ) , for Acre and a revision of its distribution in the Brazilian Amazon

We present the first records of the Wingbarred Seedeater (Sporophila americana) in Acre, Brazil. These observations, together with the published records and the specimens housed in museum collections, indicate that S. americana occurs over a considerably larger geographical area than is currently presented in the relevant literature. The occurrence of S. americana in the region of São Paulo de Olivença, in the Brazilian state of Amazonas indicates the potential existence of a sympatric zone with the congener Caqueta Seedeater (Sporophila murallae) in the western Amazonia.

The Wing-barred Seedeater, Sporophila americana (Gmelin, 1789), is a small granivorous bird of the family Thraupidae, in which the adult male is coloured black and white, and the female is brown (Stiles 1996;Jaramillo 2011).As the immature males and females of this genus present a uniform brown colouration, the taxonomy of the group is based on the characteristics of the adult male (Stiles 1996).Until the mid-20th century, many authors considered S. americana to be part of a polyspecific complex with two disjunct groups, including the Caqueta (S. murallae Chapman, 1915) and the Variable Seedeater (S. corvina hicksii (Lawrence, 1865) and S. c. ophthalmmica (Sclater, 1860)) forms from northwestern South America (Colombia, Ecuador, and Peru), and the nominal form S. a. americana to the east, in Venezuela, the Guianas, and northern Brazil, in the states of Amapá and Pará (Ridgely and Tudor 1994).
Based on its geographic distribution and morphological differences, Stiles (1996) showed that the S. murallae form is distinct from the S. americana form, and should be considered to be a full species.Following this separation, the distribution of S. americana was limited to the coastal lowlands of Venezuela, Guyana, Suriname, French Guiana, and Brazil.In Brazil, the principal field guides have adopted the classification of Stiles (1996), limiting the distribution of S. americana to the coast of Amapá, the northern margin of the Amazon River as far west a Manaus, the lower Tapajós River, and the Negro River (Stiles 1996;Ridgely and Tudor 2009;Jaramillo 2011;IUCN 2014; Figure 1).
The plumage of S. americana is similar to that of S. murallae, the main difference being the wing of the adult male.In S. americana, there are two well-defined white bars, formed by the greater and lesser wing-coverts, while in S. murallae there is only one narrow white bar on the lesser wing-coverts, which is totally absent from the greater wing-coverts in some individuals (Jaramillo 2011).This difference in the external morphology of the two forms is considered to be a diagnostic taxonomic trait and by field guides to differentiate the species (Stiles 1996;Ridgely and Tudor 2009;Jamarillo 2011;Sigrist 2014).
The Wing-barred Seedeater inhabits open areas, where it is commonly seen in pairs or mono-or poly-specific flocks feeding on grass seeds in pastures, plantations, roadsides, the vegetation on river banks, Amazonian grassland enclaves (white sand vegetations -campinas and campinaranas), and even urban areas (Hilty and Brown 1986;Restall et al. 2006;Jamarillo 2011).
After 19 years (1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015), the geographic distribu- On 23 April 2015, an immature male was observed by EG near a female, assumed to be an adult, foraging in back gardens and cleared lots in the Jardim Europa neighbourhood (09°58ʹ06.8ʺS, 067°50ʹ48.6ʺW) of the city of Rio Branco, in the Brazilian state of Acre.On 17 May 2015, EG observed an adult male feeding on grass seeds in the same area (Figure 2).This individual was foraging together with a polyspecific flock formed by the Double-collared Seedeater (Sporophila caerulescens (Vieillot, 1823)), Lined Seedeater (Sporophila lineola (Linnaeus, 1758)), Chestnut-bellied Seedeater (Sporo phila castaneiventris Cabanis, 1849), and Blue-black Grassquit (Volatinia jacarina (Linnaeus, 1766)).On 24 August 2015, an adult male was observed and photographed in the same neighbourhood, where it foraging together with other species of seedeaters.These observations tion of S. americana proposed by Stiles (1996) is still reproduced in identification guides and specialized sites (e.g., Birdlife International and International Union for Conservation of Nature).The present study aims to amend this situation through a review of the published records and specimens deposited in museums, as well as to present new records of occurrence of S. americana in the Brazilian Amazon basin, with the objective to refine the geographic distribution of this species in Brazil.
Historical records of the species in Brazil were obtained from a comprehensive search of the literature and the identification of specimens deposited in scientific collections.Data on the specimens deposited in North American museums were obtained from the Vertebrate database (Vertnet 2015).The data on the specimens deposited in the Goeldi Museum (Museu Paraense Emílio Goeldi: MPEG) in Belém were kindly provided by the curators in response to a formal request.The Brazilian WikiAves site (Wikiaves represent the first records of S. americana in Acre, and the southwestern limit of the occurrence of the species in Brazil (Figure 1; Table 1).
As in Acre, S. americana has been observed frequently by DP, DPG, and ACGL in the area surrounding the town of Tefé, in the Brazilian state of Amazonas (03°22ʹ44.40ʺS, 064°42ʹ39.96ʺW).On 11 July 2015, a solitary male (Figure 3) was observed at 5:30 pm feeding on grass seeds on the outskirts of the town.On the following day, a male was observed foraging together with a female, and a third record was obtained on 19 July 2015 at 08:20 am near the location of the first two sightings.These sightings were all obtained within a 300 m radius at the outskirts of the town's urban area.These observations confirm the occurrence of the species approximately 470 km west of Manacapuru, also in Amazonas (Figure 1, number 4), the western extreme of the distribution of the species, as defined by Stiles (1996).
The literature search provided evidence of the occurrence of S. americana within the area predicted by Stiles (1996) and the IUCN (2014), but also indicated that the species can be found outside the range limits proposed by current field guides (Table 1).Vasconcelos (2004) first recorded S. americana in the Brazilian state of Maranhão, in the municipality of Açailândia, where two males were observed by audio recording.In the western extreme of the state of Pará, Guilherme (2014) recorded and collected a number of S. americana specimens along the margin of an alluvial forest, and in an enclave of white sand vegetation, at São Pedro, a locality located within the Amana National Forest, in the municipality of Itaituba.In the state of Amazonas, Borges et al. (2001) and Borges and Almeida (2011) recorded the species in the Jaú National Park (e.g., Seringalzinho).During a survey of the biodiversity of the middle Madeira River, Cohn-Haft et al. (2007) recorded S. americana in both the Madeira-Aripuanã interfluve and on floodplain islands of the Madeira River itself.Pacheco (1993) also recorded S. americana in anthropogenic environments, e.g., plantations, and pastures as well as islands and swamps in the Mamirauá Sustainable Development Reserve, on the northern margin of the middle Solimões River (Figure 1; Table 1).
The survey of the specimens deposited in American museums and the Brazilian Goeldi Museum (Table 1) also showed that the Wing-barred Seedeater occurs in a much larger area of the Brazilian Amazon basin than was previously thought.In 1923, S. M. Klages collected a male S. americana in São Paulo de Olivença, Amazonas (Table 1).This specimen (YPM ORN 031498) deposited in the Peabody Museum of Natural History (Connecticut, USA), indicates that the species was originally found in the western extreme of the state of Amazonas, approximately 1,000 km due west of the western limit of the geographic distribution of the species, as proposed by Stiles (1996) and the IUCN (2014) (Figure 1, number 5).In addition, the specimens collected in southern Amazonas (Humaitá) and in Pimenta Bueno (Rondônia), to the south, and Boa Vista (Roraima), to the north, extend considerably the known distribution of S. americana in Brazil (Figure 1; Table 1).Based on photographs published on WikiAves (2015), it is possible to confirm the presence of S. americana in several cities from northern Tocantins state (Couto Magalhães, Santa Fé do Araguaia and São Miguel do Tocantins).
The compilation of all the available data permits the redefinition of the distribution of S. americana in Brazil and confirms its occurrence in all states of the country's northern region (Figure 1; WikiAves 2015).The presence of the species in São Paulo de Olivença indicates that S. americana may occur in sympatry with S. murallae in the western extreme of Amazonas state (Figure 1).The evidence suggests that S. americana has always been present along both sides of the Solimões/Amazon river   in Amazonas and Pará states and has expanded its area of occurrence by dispersing along the main highways (e.g., the Transamazônica [BR-230], BR-364, BR-319, and BR-174) that crisscross northern Brazil.

Figure 1 .
Figure 1.Geographic distribution of the Wing-barred Seedeater (Sporophila americana).The hatched area represents the distribution proposed by Stiles (1996), and the watermark, the area proposed by the IUCN (2014).The crosshatched area represents the distribution of the Caqueta Seedeater (Sporophila murallae).The red dots represent the localities recorded in the present study, published records, and from museum specimens, and are numbered as in Table1.

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Guilherme et al. | First record of the Wing-barred Seedeater from the state of Acre

Table 1 .
Records of the Wing-barred Seedeater (Sporophila americana) obtained from the present study, published literature, and museum specimens.AMNH: American Museum of Natural History; CM: Carnegie Museum of Natural History; LACM: Nattural History Museum of Los Angeles; MCZ: Museum of Comparative Zoology, Harvard University; MPEG: Museu Paraense Emílio Goeldi (Goeldi Museum), Belém, Pará (Brazil); YPM: Peabody Museum of Natural History, Yale University.The site codes correspond to those in Figure 1.Guilherme et al. | First record of the Wing-barred Seedeater from the state of Acre