Nest removal by humans creates an evolutionary trap for Amazonian freshwater turtles

The study was conducted by a Master’s student (Andressa Valerio) and two researchers (Dr. Fernanda Michalski and Dr. Darren Norris) of the Post-Graduation Program in Tropical Biodiversity (PPGBio), and also of the PPG in Ecology of Federal University of Rio Grande do Sul (I Quintana, FG Becker) and State University of New York (JP Gibbs). The results were published in the Journal of Zoology [1]

Avoiding predators is important for the survival of prey species and turtles have evolved a number of characteristics that have protected them over millennia. However, human hunting of adults and eggs is threatening many freshwater turtle populations. The Yellow‐spotted River Turtle (Podocnemis unifilis) is widespread across the Amazon Basin, but like many other turtles their populations have been decimated by humans. Both eggs and adults of P. unifilis have been exploited since the pre‐colonial period (pre 18th century) and are still consumed by indigenous and riverine communities across Amazonia. Although the Yellow‐spotted River Turtle has been widely studied over decades it remains unclear if they have any behavior or response that can help the members of surviving populations avoid predation by humans. To understand if female Yellow‐spotted River Turtles were able to avoid human hunting the researchers monitored 73 nesting sites along 118 km of rivers in the eastern Brazilian Amazon. They found that despite the wide availability of alternative nesting habitats, turtles do not appear to be capable of avoiding hazardous nesting sites associated with increased egg harvesting by humans. Because signals used by female turtles to select nesting areas are apparently not sufficient for avoiding nesting along rivers accessible to humans, direct conservation action will be vital for persistence of these and likely other Amazonian freshwater turtles.

The original version of this release is available at https://zslpublications.onlinelibrary.wiley.com/toc/14697998/0/0

[1] I. Quintana D. Norris A. Valerio F. G. Becker J. P. Gibbs F. Michalski. 2019. Nest removal by humans creates an evolutionary trap for Amazonian freshwater turtles. Journal of Zoology. https://zslpublications.onlinelibrary.wiley.com/doi/10.1111/jzo.12689