The Neotropical otter Lontra longicaudis: a comprehensive update on the current knowledge and conservation status of this semiaquatic carnivore

Abstract

1. The Neotropical otter Lontra longicaudis is a widespread semiaquatic carnivore living in a wide variety of environments in both fresh-water and salt-water ecosystems. We summarise the current knowledge on distribution, ecology, behaviour, evolution and conservation status of the species, and highlight the main threats that have been affecting it as well as priority actions for securing its survival. 2. The current geographical range of Lontra longicaudis is discussed, as well as several efforts that have been made to update knowledge of the range. Throughout its known distribution area, the Neotropical otter has high genetic diversity, and recent molecular research suggests that variations in genetic diversity are related to geography. Taxonomic issues regarding the existence of subspecies persist, mainly due to limited sampling in key portions of the species' range. 3. Although the Neotropical otter is widely distributed in Latin America and has flexible behaviour, it is subjected to a variety of threats, which lead this otter to be officially considered Threatened in several countries within its geographical range. 4. The species still faces an uncertain future due to the impact of human activities, thus justifying its classification as Near Threatened in the International Union for Conservation of Nature's Red List. The real level of human-otter conflicts and the impact of modified environments on Neotropical otter populations are still unclear, and must be a priority focus of future studies. 5. There is an urgent need to increase our knowledge on aspects of the Neotropical otter's biology, such as reproduction, generation time, behaviour, physiology, distribution limits, sanitary aspects, evolution and taxonomy. Understanding these topics is vital to ensure the long-term survival of the species, both at the local and at the regional scale, as well as to provide the basis for environmental education actions involving local riverside human communities.

Relationship of Neotropical otter vestiges with environmental and anthropogenic factors

“…Neotropical otters also prey on small farm animals, such as ducks and chickens, which roam freely in the riverside communities in our study area (Barbieri et al 2012). In this context, the presence of domestic dogs near riverine communities appears to cause otters to become nocturnal (Rheingantz et al 2016(Rheingantz et al , 2017a.…”

“…Fishermen also reported that they often dress up a scarecrow with clothes with vibrant colors, such as red, to scare off otters from fishing nets. Otters are frequently killed in retaliation for stealing fish (Barbieri et al 2012), yet the impact of such human-induced mortality on Neotropical otter populations is not known (Rheingantz et al 2017a). Conflicts between fishermen and otters are common worldwide [e.g., Lutra lutra in the Czech Republic (Poledníková et al 2013) and Poland (Kloskowski, 2011), Pteronura brasiliensis in Brazil (Rosas-Ribeiro et al 2012) and Peru (Recharte et al 2008), and Lontra longicaudis among artisanal fishermen in southeastern Brazil (Barbieri et al 2012).…”

Baited videos to assess semi-aquatic mammals: occurrence of the neotropical otter Lontra longicaudis (Carnivora: Mustelidae) in a marine coastal island in São Paulo, Southeast Brazil

“…Studies concerning the environmental degradation and population dynamics, as well as the long-term monitoring, behavior, and ecological aspects of the species are valuable (Almeida and Pereira 2017;Rheingantz et al 2017b). For these topics, BRUVs can be also a useful tool.…”

“…The neotropical otter Lontra longicaudis (Olfers, 1818) is a widely distributed semi-aquatic carnivorous mammal of the family Mustelidae, occurring from Mexico to northern Argentina (Foster-Turley et al 1990;Rheingantz et al 2017b). The species can be found in rivers, estuaries and, more rarely, in marine coastal regions (Blacher 1987;Chehébar 1990).…”

Habitat selection and diet of the Neotropical otter (Lontra longicaudis) on the Osa Peninsula, Costa Rica, and range-wide monitoring recommendations

“…The Neotropical otter (Lontra longicaudis) is currently listed as Near Threatened by the International Union for Conservation of Nature (IUCN), and the lack of basic information kept the Neotropical otter listed as Data Deficient until 2015 [1]. The majority of research to date has been carried out in Brazil and Mexico, with a lack of information from Central America [2]. Thus, there remains a lack of basic ecological information such as diet and habitat use in this region [3][4][5][6].…”