Seasonal abundance and breeding habitat occupancy of the Orinoco Goose (Neochen jubata) in western Brazilian Amazonia

Abstract

SummaryThe Near-threatened Orinoco Goose Neochen jubata is a poorly known South American sheldgoose with a declining population and range distribution. In this study, we surveyed the Orinoco Goose population along the middle reaches of the Rio Juruá, western Brazilian Amazonia, and its first-order tributaries. We quantified the seasonal abundance of geese, pinpointed their approximate breeding season, and examined their habitat associations and the potential effects of human activities on their abundance. Hunting by local villagers was also monitored to assess the offtake rate of this species. Orinoco Goose occurrence in the region was highly seasonal and restricted to the dry season. We estimated a mean dry-season encounter rate of 7.18 ± 2.45 adult individuals per 4-km section along this river. Immature individuals were seen along the river margins from August to December. The species showed a strong preference for sandy beaches and was primarily restricted to the main river channel, with few individuals occurring along tributaries. The encounter rate of this species was also significantly related to fluvial distance from the municipal urban centre and to the level of protection from hunting. Hunting of Orinoco Goose was reported in 12 of the 26 villages monitored. The seasonal appearance of the Orinoco Goose in the region indicates that this is a migratory population. Our study indicates that strict protection of the river margins, and sandy beaches in particular, along the main river channel is likely to be positive for the conservation of this species along the Rio Juruá. However, further knowledge of migration routes is critical for effective protection of both breeding and non-breeding populations.

An overview of migratory birds in Brazil

“…It is considered sedentary in most of its distribution, but there are records of small movements. It exhibits migratory behavior in the Amazon: there is a large breeding population in the Juruá River between June and October, after which disperses widely in the Amazon Basin (Carboneras, 1992a;Endo et al, 2014). Photographic and sound records available on WikiAves corroborate literature data and show that this species is present in the Amazon Basin only during the dry season (July to October), with records of breeding activity in November and December for Roraima (RR) (WikiAves, 2016).…”

Arthropod-borne agents in wild Orinoco geese ( Neochen jubata ) in Brazil

“…Orinoco goose (Neochen jubata) is an anatid species widely distributed in South America, where it occurs in central and Amazonic regions of Brazil. This anatid species is a terrestrial grazer and nests in large tree cavities, usually made by other birds (such as wood-peekers) [1][2][3]. Adults have nearly 60 cm of length and 1.200 g of weight, brown back and abdomen, yellow head and chest, black wing, red beak and feet [4,5].…”

Breeding and seasonal occurrence of the Orinoco Goose (Neochen jubata) in Brazil

“…The Orinoco Goose, Neochen jubata (Spix, 1825), is spottily distributed through an extensive region in South America, occurring from Venezuela and the Guianas to Bolivia, Paraguay, Argentina, and Brazil (Davenport et al 2013;Carboneras et al 2019). It is considered "Near Threatened" because its population estimated in 10,000-25,000 individuals appears to be declining mainly due to hunting and habitat loss (Delany and Scott 2006;Endo et al 2014;BirdLife International 2019).…”

“…For example, flocks with up to 10 individuals are commonly recorded at riverbanks during the dry season at Parque Estadual do Cantão, in a Cerrado-Amazon ecotone (Pinheiro and Dornas 2009). Also in the dry season, numerous birds occur at sandy beaches along Rio Juruá, western Brazilian Amazon (Endo et al 2014). More recently, about 300 birds were detected in the Rio Araguaia region, central Cerrado (FUNATURA 2019).…”