title: Population Estimation Methods for Free-Ranging Dogs: A Systematic Review.
abstract: The understanding of the structure of free-roaming dog populations is of extreme importance for the planning and monitoring of populational control strategies and animal welfare. The methods used to estimate the abundance of this group of dogs are more complex than the ones used with domiciled owned dogs. In this systematic review, we analyze the techniques and the results obtained in studies that seek to estimate the size of free-ranging dog populations. Twenty-six studies were reviewed regarding the quality of execution and their capacity to generate valid estimates. Seven of the eight publications that take a simple count of the animal population did not consider the different probabilities of animal detection; only one study used methods based on distances; twelve relied on capture-recapture models for closed populations without considering heterogeneities in capture probabilities; six studies applied their own methods with different potential and limitations. Potential sources of bias in the studies were related to the inadequate description or implementation of animal capturing or viewing procedures and to inadequacies in the identification and registration of dogs. Thus, there was a predominance of estimates with low validity. Abundance and density estimates carried high variability, and all studies identified a greater number of male dogs. We point to enhancements necessary for the implementation of future studies and to potential updates and revisions to the recommendations of the World Health Organization with respect to the estimation of free-ranging dog populations.
authors.affiliation: Departamento de Endemias Samuel Pessoa, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brasil.|Campus Centro-Oeste Dona Lindu, Universidade Federal de São João del Rei, Divinópolis, Minas Gerais, Brasil.
authors.forename: Vinícius Silva
authors.initials: VS
authors.lastname: Belo
authors.affiliation: Departamento de Epidemiologia - Instituto de Medicina Social, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil.
authors.forename: Guilherme Loureiro
authors.initials: GL
authors.lastname: Werneck
authors.affiliation: Campus Centro-Oeste Dona Lindu, Universidade Federal de São João del Rei, Divinópolis, Minas Gerais, Brasil.
authors.forename: Eduardo Sérgio
authors.initials: ES
authors.lastname: da Silva
authors.affiliation: Departamento de Endemias Samuel Pessoa, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brasil.
authors.forename: David Soeiro
authors.initials: DS
authors.lastname: Barbosa
authors.affiliation: Departamento de Endemias Samuel Pessoa, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brasil.
authors.forename: Claudio José
authors.initials: CJ
authors.lastname: Struchiner
mesh_terms: D000827:Animal Welfare; D000818:Animals; D004285:Dogs; D006801:Humans; D011155:Population Control; D011156:Population Density