Spider monkeys, the misunderstood assumptions of distance sampling and the pitfalls of poor field design

  • Antonio Christian de AndradeEmail author
  • Tiago A. Marques
  • Stephen T. Buckland
Letter to the Editor

Information on wildlife population size is fundamental for effective conservation actions. The most popular method used to obtain information on population size is distance sampling, and the most commonly used form of distance sampling is line transect sampling (Buckland et al. 2015; Spaan et al. 2019). To be useful, population size estimates need to be unbiased and precise, allowing detection of changes that are relevant to conservation managers. We agree with Spaan et al. (2019) that there is a need for method standardization to compare estimates across time and space, and thus aid conservation decisions.

Spaan et al. ( 2019) compare methodologies for estimating the density of spider monkeys Ateles geoffroyi. They consider two surveys, survey 1 in the home range of a habituated group of known size, and survey 2 of a wider region contiguous with the home range of survey 1. True abundance is only known for survey 1. The authors claim that their analyses indicate that the Kelker strip...



TAM thanks partial support by CEAUL (funded by FCT—Fundação para a Ciência e a Tecnologia, Portugal, through the project UID/MAT/00006/2019).


  1. Buckland ST, Plumptre AJ, Thomas L, Rexstad EA (2010a) Line transect sampling of primates: can animal-to-observer distance methods work? Int J Primatol 31:485–499CrossRefGoogle Scholar
  2. Buckland ST, Plumptre AJ, Thomas L, Rexstad EA (2010b) Design and analysis of line transect surveys for primates. Int J Primatol 31:833–847CrossRefGoogle Scholar
  3. Buckland ST, Rexstad EA, Marques TA, Oedekoven CS (2015) Distance sampling: methods and applications. Springer, New YorkCrossRefGoogle Scholar
  4. Gates CE (1969) Simulation study of estimators for the line transect sampling method. Biometrics 25:317–328CrossRefGoogle Scholar
  5. Spaan D, Ramos-Fernandez G, Schaffner CM, Smith-Aguilar SE, Pinacho-Guendulain B, Aureli F (2019) Standardizing methods to estimate population density: an example based on habituated and unhabituated spider monkeys. Biodiv Conserv 28:847–862CrossRefGoogle Scholar

Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.Departamento de Engenharia e Meio AmbienteUniversidade Federal da ParaibaRio TintoBrazil
  2. 2.Centre of Urban Enviroments, University of Toronto MississaugaTorontoCanada
  3. 3.Centre for Research into Ecological and Environmental Modelling, University of St AndrewsSt AndrewsUK
  4. 4.Departamento de Biologia Animal, Centro de Estatística e Aplicações, Faculdade de Ciências, Universidade de LisboaLisbonPortugal

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