Giant otter Pteronura brasiliensis density and abundance in Llanos Orientales de Colombia in the Orinoco basin
GERMÁN GARRO TE,BEY KE R CAS T A Ñ E D A ,J OS E MANUE L E SCOBAR,LAURA P ÉREZ BRAY A N MAR Í N ,J AC I N T O TERÁN and F E RNANDO TRUJILL O
Abstract The giant otter Pteronura brasiliensis, categorized as Endangered on the IUCN Red List, was once widely distributed throughout South America. By the middle of the 20th century the giant otter had become locally extinct along the main rivers of the Orinoco basin. Although some populations seem to have recovered, the paucity of in- formation available does not permit a full evaluation of the species’ conservation status. The objective of this study was to estimate the abundance and density of the giant otter population along the Orinoco river in the municipality of Puerto Carreño, Vichada, Colombia, where there is impor- tant commercial and recreational fishing. Thirty-nine linear km were surveyed, repeatedly, with a total of 315 km of sur- veys. Population size was estimated by direct counts of in- dividuals. All individuals detected were photographed and identified individually from their throat pelage patterns. In total, 30 otters were identified, giving a minimum density of 0.77 individuals per km, one of the highest reported for the species in Colombia. Given the high density in this well-developed area, our results highlight the importance of this population for the conservation of the species.
Keywords Colombia, density estimation, giant otter, Orinoco river, Pteronura brasiliensis, survey
et al., 2015), was once widely distributed throughout South America from northern Argentina to Colombia and Venezuela (Carter & Rosas, 1997). However, because of the commercial value of its fur, overhunting in the 1950s and 1960s led to the collapse of its populations and extinc- tion over a large part of its original range (Carter & Rosas, 1997). In the 1960s in Llanos Orientales de Colombia (Orinoco Basin) the species was present only in the remote upper reaches of the rivers (Medem, 1968). More recent
T GERMÁN GARROTE (Corresponding author,
orcid.org/0000-0002-6974-4513),
JOSE MANUEL ESCOBAR and LAURA PÉREZ Instituto de Biología de la Conservación (IBiCo), c/ Neblí, 13. 28230, Madrid, Spain E-mail
gergarrote@gmail.com
BEYKER CASTAÑEDA,BRAYAN MARÍN,JACINTO TERÁN and FERNANDO TRUJILLO Fundación Omacha, Bogotá, Colombia
Received 16 May 2019. Revision requested 13 September 2019. Accepted 9 January 2020. First published online 25 November 2020.
FIG. 1 The study area in eastern Colombia, showing river sections and lagoons surveyed.
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (
http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. Oryx, 2021, 55(5), 779–782 © The Author(s), 2020. Published by Cambridge University Press on behalf of Fauna & Flora International doi:10.1017/S0030605320000058
he giant otter Pteronura brasiliensis, categorized as Endangered on the IUCN Red List (Groenendijk
studies have shown that the species is nowpresent throughout the area (Carrasquilla, 2002;Díaz, 2007). However, themeth- ods used inthese studies didnot provide information that per- mits an evaluation of the species’ conservation status. Our objective thereforewas to estimate the abundance and density of the giant otter population along the Orinoco river, and its tributaries and lagoons, in the municipality of Puerto Carreño, in Vichada, Colombia. This study was carried out along the Orinoco river in the
municipality of Puerto Carreño in the north-east of the Department of Vichada (Fig. 1). This department lies at al- titudes of 50–100 m, has a mean annual temperature of 28 °C, and the mean total annual precipitation is 2,176 mm, with dry (December–March) and rainy (April–November) seasons (IGAC, 1996). The study area includes the Bojonawi private nature reserve, and lies in the El Tuparro Biosphere Reserve. Important commercial and recreational fishing activities occur in this area.
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