Defining Neotropical Otter Lontra Longicaudis Distribution, Conservation Priorities and Ecological Frontiers

Abstract

Understanding a species' occurrence requirements is essential for its conservation, and species distribution models (SDMs) are a powerful tool for this purpose. Here we estimated a SDM based on actual distribution information, in relation to climatic, hydrological, human population, and vegetation data sets, to understand the ecological requirements and geographic distribution of the Neotropical otter Lontra longicaudis, a species whose habitat requirements and conservation needs are mostly unknown. Using MaxEnt, we defined its potential distribution and most suitable areas to indicate priority areas for research and to analyze the efficiency of Protected Areas (PAs). Our findings suggest that the range of Neotropical otters could extend beyond their present estimated distribution, adding new areas in northeastern Brazil, Andean region, west Ecuador, Venezuela, Peru, Mexico, and Argentina, with higher suitability in rain forests (especially Atlantic and Amazon Forests). We also found that PAs are the most suitable areas for otter distribution. Although better than non-protected areas, PAs are close to the median of the suitability values, indicating that they still can be improved to conserve otters. Annual temperature and human population density explained most data variance in our model. We suggest the change of the actual status of Neotropical otter to Least Concern or Near Threatened categories. We recommend verifying the possible sympatry with other otters, and demonstrate that rudimentary and/or occasional recent data of occurrence can also be used in SDMs and contribute to species conservation.Keywords: distribution range, Neotropical otter, niche modeling, reserve design, suitability Resumo Compreender os requisitos para a ocorrência de uma espécie é fundamental para sua conservação, e os modelos de distribuição de espécies (SDM) são uma ferramenta poderosa para essa finalidade. Aqui nós estimamos um SDM a partir de informações reais de distribuição, em relação a conjuntos de dados climáticos, hidrológicos, de população humana e de vegetação para entender as exigências ecológicas e a distribuição geográfica da lontra Neotropical Lontra longicaudis, espécie cujos requisitos de habitat e necessidades para a sua conservação são praticamente desconhecidos. Usando MaxEnt, definimos sua distribuição potencial e as áreas mais adequadas para a espécie a fim de indicar áreas prioritárias para pesquisa e analisar a eficácia das áreas protegidas (APs). Nossos resultados indicam que a distribuição da lontra neotropical poderia se estender além de sua distribuição atual estimada, adicionando novas áreas no nordeste do Brasil, na região andina, no oeste do Equador, na Venezuela, no Peru, no México e na Argentina, com maior adequabilidade em florestas tropicais (especialmente Mata Atlântica e Floresta Amazônica). Descobrimos também que APs são as áreas mais adequadas para a distribuição de lontra. Porém, embora sejam mais adequadas do que áreas não protegidas, as APs estão perto da mediana dos valores de adequa...

New records and update on the geographic distribution of Lontra longicaudis (Olfers, 1818) (Carnivora: Mustelidae) in Seasonally Dry Tropical Forests of northeastern Brazil

“…Thus, our results indicate a real gap in the current species distribution at this biome. The existence of such gap is also corroborated by the areas of lesser suitability values in northeastern Brazil, estimated by the previously published species distribution model (Rheingantz et al 2014).…”

“…In a recent study, Rheingantz et al (2014) estimated a species distribution model for L. longicaudis and suggested the expansion of its current distribution to new areas, covering Brazil's Northeast Region, including Caatinga biome. Following recommendations by Rheingantz et al (2014), and based on existing occurrence data, the distribution map of L. longicaudis was updated, and now the entire Brazilian territory is included within its distribution range (IUCN 2015).…”

“…Following recommendations by Rheingantz et al (2014), and based on existing occurrence data, the distribution map of L. longicaudis was updated, and now the entire Brazilian territory is included within its distribution range (IUCN 2015). Although the map is presented as a uniform polygon, Rheingantz et al (2014) pointed the importance of gathering occurrence data in areas with little information, and recommended that northeastern Brazil be a priority area for future studies; this region represents one of the driest areas within the range of the Neotropical Otter.…”

Predators, Prey and Habitat Structure: Can Key Conservation Areas and Early Signs of Population Collapse Be Detected in Neotropical Forests?

“…This historical absence of large-scale deforestation makes this region the largest repository of tropical forest vegetation on Precambrian terrain in the world [14]. The region is an area of major importance for conservation of several large terrestrial mammals, including peccaries ( Tayassu pecari and Pecari tajacu ), Brazilian tapir ( Tapirus terrestris ) [15], giant and neotropical otters ( Pteronura brasiliensis and Lontra longicaudis ) [16, 17], and jaguar ( Panthera onca ) [18]. Threats to their survival are nevertheless present and growing in the region.…”

“…Recently, many species have been studied using the latest niche modeling tools to improve knowledge of ecological requirements and conservation opportunities [17,25,26]. Nevertheless, approaches considering the conservation status of both predator and prey species, the relations between their respective status and the prospectives for the future are scarce and difficult to implement.…”