Estimating population sizes to evaluate progress in conservation of endangered golden lion tamarins (Leontopithecus rosalia)

PLoS One. 2019 Jun 5;14(6):e0216664. doi: 10.1371/journal.pone.0216664. eCollection 2019.

Abstract

Efforts to reverse the decline of endangered golden lion tamarin monkeys have been relatively successful because the Brazilian organization dedicated to the species' conservation (Associação Mico-Leão-Dourado, AMLD) relies on science-based computer modeling to determine the number of tamarins necessary to achieve demographic and genetic goals, and a process of strategic planning to achieve those goals. Accurate estimates of the numbers of tamarins in forest fragments are essential to evaluate progress in achieving goals and adapt strategies as necessary. In this report we present the results of a new method to survey the number of tamarins in the wild, a modification of the point transect with lures procedure. Using this method, we estimate that in 2014 there were approximately 3,700 golden lion tamarins in 41,400 hectares of Atlantic Forest. Of these, 59% are from remnant wild populations, 34% are descendants of captive-born reintroduced animals and 7% are descendants of wild translocated groups. The number of tamarins and amount of forest estimated in this survey exceeded values necessary to meet AMLD's definition of a viable population, determined to be 2,000 tamarins in 25,000 hectares of connected and protected forest. However, the seven forest blocks and their tamarin populations are not yet adequately connected and protected. AMLD's strategic plan to achieve a viable population of golden lion tamarins includes 12 strategies that mitigate these and other threats or contribute directly to the conservation goal. The point transect with lures survey method provides a way to evaluate progress in achieving that goal and adapt strategies as appropriate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Conservation of Natural Resources*
  • Endangered Species / statistics & numerical data*
  • Geography
  • Leontopithecus*
  • Population Density
  • Surveys and Questionnaires

Supplementary concepts

  • Leontopithecus rosalia

Grants and funding

CRRM was funded by fellowships from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001 and from the Conselho Nacional de Pesquisa (CNPQ) fellowship number PQ 309660/2013. The Associação Mico Leão Dourado received funds from the Conservation Food and Health Foundation, Copenhagen Zoo, Disney Conservation Fund, Fundação Grupo Boticário, Lion Tamarins of Brazil Fund, Philadelphia Zoo, Save the Golden Lion Tamarin and Zoo Atlanta. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.