Occurrence of the Brazilian Merganser (Mergus octosetaceus) in the Southern Border of the Espinhaço Range, Minas Gerais, Brazil GABRIEL ARVELINO DE PAULA1, MARCONI CAMPOS CERQUEIRA JÚNIOR1 AND RÔMULO RIBON1,2 1Laboratório de Ornitologia, Departamento de Ciências Biológicas, Instituto de Ciências Exatas Biológicas, Universidade Federal de Ouro Preto, CEP 35400-000, Ouro Preto, Minas Gerais, Brazil 2Current address: Museu de Zoologia João Moojen, Departamento de Biologia Animal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil, CEP 36570-000 Corresponding author; Internet: [email protected] Abstract.—We report a new locality for the Brazilian Merganser (Mergus octosetaceus), a critically endangered spe- cies from Southern and Central South America. The species’ range is considerably extended to the East, and a new habitat and basin used by the species are given. The species was found near the city of Ouro Preto, Minas Gerais State, Brazil, located in a transition zone between the Cerrado and the Atlantic Forest biomes. Our finding improve a little bit the hope for the conservation of the species but more detailed studies to determine if there is a resident population, or if we recorded a vagrant bird, are necessary. Received 11 June 2007, accepted 10 November 2007. Key words.—conservation, Doce River, Espinhaço range, Merganser, Mergus octosetaceus, Ouro Preto, threatened species. Waterbirds 31(2): 289-293, 2008 The Brazilian Merganser (Mergus octoseta- viduals in southwestern Bahia State (Pineschi ceus) is a critically endangered bird (BirdLife and Yamashita 2000). In Minas Gerais State International 2007) inhabiting clear water the species was observed by G.T. Mattos in and rapids, deeper than one m and more the Salitre creek, near Salitre de Minas coun- than three m wide, where exposed rocks are ty, in 1973 (Sick 1997), although currently used for roosting (Silveira and Bartman the species is suspected to be confined to the 2001). Most of the time the birds feed in Serra da Canastra National Park and neigh- clear water, weak flow natural pools (Silveira borhoods (Andrade 1998). Old records are and Bartman 2001), with submersed micro- from Mato Grosso do Sul, Rio de Janeiro, São phytes and riverine forests (Pineschi and Ya- Paulo, and Santa Catarina states, where it is mashita 2000). Territory is estimated to nine believed to be extinct (Stattersfield 2000). km of linear river, and can be related to food The species is also found in the upper Parana and nest sites availability (Silveira and Bart- River, Paraguay, with the last record in 1984 man 2001), as trunk holes in gallery forests by N. López (Hughes et al. 2006). In Argenti- trees (Partridge 1956) and crevices in rocks, na the species is restricted to the Misiones at regions dominated by open grassy fields or Province (Partridge1956), where it is in the rupestrian fields (Lamas and Santos 2004). brink of extinction (Benstead et al. 1994; Shyness and ability to detect intruders make Hughes et al. 2006). behavioral observations of the Brazilian Mer- ganser a difficult task and its biology poorly METHODS known (Silveira and Bartman 2001). Brazilian Merganser have been recorded Observations were made with binoculars Tasco 8 × 21 × in a couple of localities in Brazil: upper To- mm and Zenit 10 50 mm. Calls were tape-recorded with a Sony TCM 5000 EV and a Sennheiser ME 66 micro- cantins river in Nova Roma county (Sick phone, and housed at the Arquivo Sonoro Elias Coelho 1997), Chapada dos Veadeiros National Park (ASEC, Universidade Federal do Rio de Janeiro). Photo- (Yamashita and Valle 1990), and Emas Na- graphs and a movie were also used for documentation (Canon EOS-500; 75-300 mm lenses). From April to Au- tional Park (Collar et al. 1992), in Goiás State, gust 2004 four visits a week were made to the study area. and Jalapão State Park (Braz et al. 2003), in Tocantins State. A small population was Study Area found in the Tibagi river, Paraná State (Anjos Observations were made at Itacolomi State Park et al. 1997), and there are records of 3-4 indi- (IEP) (20°22’30”-20°30’00”S, 43°32’30”-43°22’30”W), 289 290 WATERBIRDS roughly 100 km from Belo Horizonte city, Minas Gerais individual did not fly, but only called briefly State. The park extends through Ouro Preto and Mari- and moved away, swimming to the opposite ana counties, protecting most of the Serra do Itacolomi, the southernmost branch of the Espinhaço Range (Mes- side of the lagoon. The literature describes sias et al. 1997). shiner birds from other regions, as they fly The IEP covers some 7,000 ha and its vegetation is immediately after detecting human pres- classified as lower-montane pluvial forest, having also ri- parian pluvial forest and rupestrian fields (Messias et al. ence (Partridge 1956; Yamashita and Valle 1997). The park is situated in the Rio Gualaxo basin, a 1990; Silveira and Bartmann 2001). The tributary of Doce River. The main watercourses are Praz- specimen at IEP often fed on small fish (of eres and Domingas creeks and the Belchior stream. The “da Curva” (20°25’85”S, 43°30’54”W), is an artificial la- about ten cm of total length) which are goon, at 1,225 m a.s.l., with two m of maximum depth, quickly swallowed. and scattered trees bordering it. It is near the headquar- The duck at IEP had slight morphologi- ters of the park and is supplied by the Manso creek, which is no more than one m wide and is surrounded by cal differences, compared with individuals closed, low vegetation. from other regions, as it had a mandible marked smaller than the maxilla, and had a RESULTS well visible gap in the feathers of the top of the head (Fig. 1). Besides morphology, the Although there is one record in 1819 for shyer behavior and habitat used were very the das Velhas river (Collar et al. 1992), near different, when compared to birds at SCNP Ouro Preto, there is no indication of the ex- (M.C.C., Jr. and G.A.P., pers. obs.). It is not act municipality. The first sighting in this possible to precise why the beak and crown study of the Brazilian Merganser occurred in were defective, but the injury could have 24 April 2004, at 13.00 h, when a single indi- been occurred due to a predator attack (wild vidual was observed in the da Curva lagoon. animals such as otter, or feral dogs which are The record extends the species range 300 common at IEP), or even human captivity. km to the east, from the site where the better Genetic problems could also be the cause of known population (and maybe the largest the morphological differences, but parsimo- one) of the Brazilian Merganser still re- ny would be in favor of the previous explana- mains—the Serra da Canastra National Park tions. The specimen was recognized as a (SCNP). In 21 May the bird was photo- male, judging for its characteristic call (L. F. graphed, and some behavioral observations Silveira, com. pess.). were made. The calls were tape-recorded in In July 2004 the individual changed rest- 19-23 June. The same individual was ob- ing sites too often. It was also more secretive served until August of the same year. In four than in the previous months, hiding more of the 80 visits to the lagoon the bird was not frequently in the vegetated bank. These seen or heard. changes coincided with the land removing While feeding, the bird in IEP showed and car traffic due to the construction of a the same behavior described by Bartmann (1988) for the birds in the SCNP—submerg- ing of the head followed, or not, by diving. The bird at IEP spent most of the time rest- ing and preening over a partially submerged trunk. When played back the bird respond- ed promptly in an aggressive way, approach- ing until one m from the authors. During these episodes the bird stretched its neck, lifted its tail and vocalized intensively, as de- scribe by Silveira and Bartmann (2001). As described for other regions, the bird at IEP was extremely keen in detecting the Figure 1. Male of Brazilian Merganser (Mergus octoseta- human approaching, even over long distanc- ceus) at Itacolomi State Park. Note the gap in the crown es (Braz et al. 2003). When frightened, the and the marked smaller mandible (I. R. Lamas). M. OCTOSETACEUS RANGE EXTENSION 291 camping area near the lagoon, with increas- ing tourist numbers, and frequent visits of an otter (Lontra longicaudis) in the lagoon. The lagoon where the Brazilian Mergan- ser was found is quite different from those given by the literature as the only habitat where the species is found (rapids of clear wa- ter rivers, near headwaters) (Yamashita and Valle 1990, Stattersfield and Capper 2000). The lagoon is formed by a straight (0.5-1 m wide), shallow (0.1-0.5 m) and calm creek, and has a muddy bed. These characteristics strongly contrasts with the rocky beds of the watercourses of the SCNP (I. R. Lamas, pers. comm.), and those from the other sites where the species have been found. However, the lagoon is an exception to the rule as there are some watercourses, in and around IEP, whose characteristics matches perfectly those of typical Brazilian Merganser habitat. Additionally this is the first time the species is recorded at the Doce River basin, which has approximately 853 km from its head to mouth, and could be searched for the mer- Figure 2. Recent (last 20 years) and historical records of ganser, at least near its head.