Description

This is an average sized, robustly built otter, very similar in appearance to the other American river otters. The tail can be notably long, forming more than a third of the body length. They are around 1.5m long, weighing 25kg. The species shows sexual dimorphism - the male is generally 20-25% larger than the female. Apart from the longer tail, these otters look like Southern and North American River Otters, and for a long time, the relationships between the species were obscure, and many species identified that are now considered subspecies and local races. Rhinarium shape varies a great deal. This species does not appear to be social. The female only tolerates the male during oestrus, and, like the Eurasian Otter, groups of otters seen together appear to be females with cubs. The main prey of the Neotropical Otter is fish (slow and easy to catch, conspicuous and palatable), followed by crustaceans. Insects are locally much used.

Habitat

These versatile otters are found in a very wide variety of environments: permanent, seasonal and intermittent rivers, streams and creeks, freshwater Lakes, marshes and pools, saline, brackish or alkaline lakes, marshes and pools, shrub-dominated wetlands, geothermal wetlands, permanent inland deltas , shallow bays, rocky shores, estuaries, intertidal marshes, coastal freshwater, brackish and saline lagoons, reservoirs, ponds, fish farms, excavations, wastewater treatment areas, seasonally flooded and irrigated agricultural land, canals, drainage ditches (such as among rice and sugar cane plantations in Guyana), bogs, fens, swamps and peatlands. They can live in evergreen and deciduous forests, in warm and cool climates, by the sea or in the rainforest. They have been seen in the swampy areas of cushion plants and sedges surrounding glacial lakes in the High Andes of Ecuador at an altitude of 3885m.

Distribution

The species ranges from northern Argentina up through south and central America to Mexico.  There is then an otter-free arid zone between it and the North American River Otter.

Conservation Status

Red List Category DD (Data Deficient)
Year Assessed 2004
Assessor Waldemarin, H.F.
Evaluators Reuther, C. & Hussain, S.A. (Otter Red List Authority)

The species seems to be widespread, and its range does not seem to have changed, but there is no data available about population size, composition or distribution, so changes cannot be determined.

(Source: IUCN Red List)

Current Concerns

There are two major threats to the species in Latin America: habitat destruction and water pollution. This otter was declared a protected species in 1973, however, it is still being hunted illegally.

Leading Researchers

Helen Waldemarin, J. Quadros, E.L.A. Monteiro-Filho

Key Publications

General

• Harris, C.J. (1968). Otters: A Study of the Recent Lutrinae. Weidenfeld and Nicholson, London
• Larivière, S. (1991) - Lontra longicaudis. Mammalian Species, 609:1-5.

Useful Links

• The IUCN Red List Waldemarin, H.F. 2004. Lontra longicaudis . In: IUCN 2006. 2006 IUCN Red List of Threatened Species.