Buitrón-Jurado An aberrant record of Hoatzin Opisthocomus hoazin ( Statius Muller , 1976 ) ( Aves : Opisthocomidae ) in Venezuela

I report an aberrant record of Hoatzin Opisthocomus hoazin in the Andes of Lara, Venezuela. During field work in July 2011 in the Yacambú National Park, in an area of premontane cloud forest, I observed and photographed an individual of O. hoazin in El Blanquito reservoir. This is the first record of the species in Lara State, and apparently the highest record of the species in northern South America. Laboratorio de Biología de Organismos, Centro de Ecología, Instituto Venezolano de Investigaciones Científicas, Caracas 1020-A, Apartado 2032, Los Altos, Venezuela. E-mail: galobuitronj@yahoo.es Galo Buitrón-Jurado An aberrant record of Hoatzin Opisthocomus hoazin (Statius Muller, 1976) (Aves: Opisthocomidae) in Venezuela Hoatzin Opisthocomus hoazin (Statius Muller, 1776) is the only member of Opisthocomidae and one the most peculiar species of bird from South America. The phylogenetic relationship of the Hoatzin is still disputed, although it has been related to the cuckoos and more recently considered closest to the African touracos or even pigeons and doves (Hughes and Baker 1999; Sorenson et al. 2003; Hackett et al. 2008). The Hoatzin is a large bird with an unmistakable appearance which is similar to a guan due to the long tail, rounded wings and small head with a prominent crest (Restall et al. 2006). The bill is heavy and the face shows a wide naked blue facial area. Conspicuous marks in the field are the dark brown wings with broad whitish tips in the coverts, the narrow white streaks on hind neck and the mantle and the long tail with a broad buff terminal band (Hilty 2003; Restall et al. 2006). Besides its appearance, the Hoatzin’s life history is also unusual because of its near-obligate folivore diet; but unlike other birds, the hoatzin uses a microbial foregut fermentation to convert cellulose to sugars (DomínguezBello et al. 1994). The Hoatzin is widespread in South America, and it is found mainly across the Amazon Basin. It is generally found in sedentary groups along the border of rivers, oxbow lakes and slow-run streams in the lowlands (Thomas 1996). In Venezuela it is commonly found in the southwestern part of the country, mainly in the Llanos of Apure, Barinas, Portuguesa, Guárico, Cojedes and Anzoátegui states, but also in Amazonas and in the northeastern in Sucre and Delta Amacuro states (Hilty 2003). Here I report an aberrant distributional record of the Hoatzin in the Andes of Lara State, Venezuela. During fieldwork between June and July 2011 at the Yacambú National Park, Lara State, I recorded an individual perched in the border of the Blanquito reservoir (09°42′15′′ N, 69°34′22′′ W) at an elevation of 1448 m (Figure 1).The area correspond to the recreational area of the park and vegetation surrounding the reservoir is mostly secondary cloud forest. Main tree species included Myrcia, Alchornea, Cecropia and Chamaedorea palms mixed with scattered exotics as Araucaria and Eucalyptus. On 2 July 2013, an individual was spotted at a distance of 50 m from the shore of the reservoir as it remained perched motionless for several minutes without making any intent to feed in the nearest vegetation (Figure 2). During all the observation time, the bird did not sing nor tried to fly over the water, and plumage looked worn-out, especially tail tips. Other species present in the reservoir included: Caribbean Coot Fulica caribaea Ridway, 1884, Least Grebe Tachybaptus dominicus (Linnaeus, 1766) and four Rusty-flanked rails Laterallus levraudi (Sclater & Salvin, 1868). The bird was searched in a second visit in August when a bird was only heard, besides being recorded in other occasion by other observers as well in the same spot, in company of Neotropic cormorants Phalacrocorax brasilianus (J.F Gmelin, 1789), although foraging activities were neither observed (G. Rodriguez pers. comm.). Hoatzin has never been recorded in cloud forest habitats previously and, in fact, they are not easily found far away from slow water courses and marshy habitats in the lowlands (Hilty 2003; pers. obs.). It was impossible to determine if the bird was a captive releasing bird, although it is very unlikely given that the species is reported as very difficult to adapt to captivity and to artificial diets (Thomas 1996). I believe that my record probably involved a vagrant, and this record is awkward considering of the weak flight abilities of the species (Thomas 1996; Ridgely and Greenfield 2001). Hoatzins have been recorded commonly up to 600 m in Ecuador and Colombia and up to 300 m in Venezuela (Ridgely and Greenfield 2001; Hilty 2003). Our record implies an increase in 1100 m of the currently known elevation range of Hoatzin in Venezuela (Hilty 2003), and it is also the westernmost record in the country separated for at least 46 km in straight line from its known range in the floodplains and llanos near to Acarigua (09°33′25′′ N, 69°12′16′′ W) in the border of Portuguesa and Lara States (Figure 1). This record is also the highest record of the species in northern South America. The previous high altitude record for the species seems to be one register in Nunpatakaime River in southeastern Ecuador at 1050 m (Freile et al., in press). Unusual records of birds have been reported in


Galo Buitrón-Jurado
An aberrant record of Hoatzin Opisthocomus hoazin (Statius Muller, 1976) (Aves: Opisthocomidae) in Venezuela Hoatzin Opisthocomus hoazin (Statius Muller, 1776) is the only member of Opisthocomidae and one the most peculiar species of bird from South America.The phylogenetic relationship of the Hoatzin is still disputed, although it has been related to the cuckoos and more recently considered closest to the African touracos or even pigeons and doves (Hughes and Baker 1999;Sorenson et al. 2003;Hackett et al. 2008).The Hoatzin is a large bird with an unmistakable appearance which is similar to a guan due to the long tail, rounded wings and small head with a prominent crest (Restall et al. 2006).The bill is heavy and the face shows a wide naked blue facial area.Conspicuous marks in the field are the dark brown wings with broad whitish tips in the coverts, the narrow white streaks on hind neck and the mantle and the long tail with a broad buff terminal band (Hilty 2003;Restall et al. 2006).Besides its appearance, the Hoatzin's life history is also unusual because of its near-obligate folivore diet; but unlike other birds, the hoatzin uses a microbial foregut fermentation to convert cellulose to sugars (Domínguez-Bello et al. 1994).
The Hoatzin is widespread in South America, and it is found mainly across the Amazon Basin.It is generally found in sedentary groups along the border of rivers, oxbow lakes and slow-run streams in the lowlands (Thomas 1996).In Venezuela it is commonly found in the southwestern part of the country, mainly in the Llanos of Apure, Barinas, Portuguesa, Guárico, Cojedes and Anzoátegui states, but also in Amazonas and in the northeastern in Sucre and Delta Amacuro states (Hilty 2003).Here I report an aberrant distributional record of the Hoatzin in the Andes of Lara State, Venezuela.
During fieldwork between June and July 2011 at the Yacambú National Park, Lara State, I recorded an individual perched in the border of the Blanquito reservoir (09°42′15″ N, 69°34′22″ W) at an elevation of 1448 m (Figure 1).The area correspond to the recreational area of the park and vegetation surrounding the reservoir is mostly secondary cloud forest.Main tree species included Myrcia, Alchornea, Cecropia and Chamaedorea palms mixed with scattered exotics as Araucaria and Eucalyptus.On 2 July 2013, an individual was spotted at a distance of 50 m from the shore of the reservoir as it remained perched motionless for several minutes without making any intent to feed in the nearest vegetation (Figure 2).During all the observation time, the bird did not sing nor tried to fly over the water, and plumage looked worn-out, especially tail tips.Other species present in the reservoir included: Caribbean Coot Fulica caribaea Ridway, 1884, Least Grebe Tachybaptus dominicus (Linnaeus, 1766) and four Rusty-flanked rails Laterallus levraudi (Sclater & Salvin, 1868).The bird was searched in a second visit in August when a bird was only heard, besides being recorded in other occasion by other observers as well in the same spot, in company of Neotropic cormorants Phalacrocorax brasilianus (J.F Gmelin, 1789), although foraging activities were neither observed (G.Rodriguez pers.comm.).
Hoatzin has never been recorded in cloud forest habitats previously and, in fact, they are not easily found far away from slow water courses and marshy habitats in the lowlands (Hilty 2003;pers. obs.).It was impossible to determine if the bird was a captive releasing bird, although it is very unlikely given that the species is reported as very difficult to adapt to captivity and to artificial diets (Thomas 1996).I believe that my record probably involved a vagrant, and this record is awkward considering of the weak flight abilities of the species (Thomas 1996;Ridgely and Greenfield 2001).Hoatzins have been recorded commonly up to 600 m in Ecuador and Colombia and up to 300 m in Venezuela (Ridgely and Greenfield 2001;Hilty 2003).Our record implies an increase in 1100 m of the currently known elevation range of Hoatzin in Venezuela (Hilty 2003), and it is also the westernmost record in the country separated for at least 46 km in straight line from its known range in the floodplains and llanos near to Acarigua (09°33′25″ N, 69°12′16″ W) in the border of Portuguesa and Lara States (Figure 1).This record is also the highest record of the species in northern South America.The previous high altitude record for the species seems to be one register in Nunpatakaime River in southeastern Ecuador at 1050 m (Freile et al., in press).Unusual records of birds have been reported in South America in the last years, including marine birds in the Andes (Jahn et al. 2010;Colorado and Ramírez 2005).Additional aberrant records of birds should be expected in Venezuela as more observers report their observations.

Figure 1 .
Figure 1.Place of record of Hoatzin Opisthocomus hoazin (green dot) in Lara State, Venezuela.The orange circles represent major cities and red dots are nearest towns to Yacambú area.Dark green area represents the species' range in Venezuela, according to Birdlife and Nature Serve (2012).