Misleading monitoring: more hatchlings do not represent turtle population recovery

Abstract

This article critiques a recent study by Lacava et al. (2024) that suggests the population of Podocnemis expansa has recovered in Brazil based on increased hatchling releases across 11 nesting areas. I present three main challenges to the study conclusions. Firstly, hatchling counts alone should not be used to assess population recovery. Secondly, the study failed to consider alternative hypotheses that could explain the observed increases, including changes in methods and effort over time. Lastly, the statistical analysis was flawed, specifically neglecting temporal autocorrelation and failing to distinguish between statistical significance and biological relevance. Reanalysis of the original data, accounting for temporal autocorrelation, revealed sustained increases in hatchlings released in only five of eleven areas, contradicting the original claim of increases in most areas. Furthermore, reanalysis suggests that methodological changes influenced results in at least one area. The study published by Lacava et al. (2024) requires correction to avoid ingenuous and potentially misleading conclusions and to more closely reflect the reality of 21st-century freshwater turtle conservation efforts.