Cooperative Fish and Wildlife Research Units Program: North Carolina
Education, Research and Technical Assistance for Managing Our Natural Resources

Rivera, S.J., K.M. Alpi, J. A. Collazo, M. K. Stoskopf. 2022. Statistical Methods Used In Research Concerning Endangered and Threatened Animal Species of Puerto Rico: A Meta-study. Caribbean Journal of Science.


A concern about statistics in wildlife studies, particularly of endangered and threatened species, is whether the data collected meet the assumptions necessary for the use of parametric statistics. This study identified published papers on the nine endangered and six threatened species found only on Puerto Rico using 5 different databases. The results from the database Zoological Record identified the most articles, including all identified by the other databases. Of the 220 articles identified, 113 included some form of statistics, 28 used only descriptive statistics, 42 included parametric statistics, 24 used only nonparametric statistics, and 19 reported both parametric and nonparametric statistical analyses. This meta-study showed that the percentage of articles with no statistical treatment decreased in the most recent 20 years and that although parametric statistics continue to be most commonly used in published wildlife studies of Puerto Rican wildlife, there has been a distinct increase in the use of nonparametric statistics over time.