Sex ratios for the Chelydra serpentina are actually temperature dependent just like the sea turtles we studied in class. Interestingly the males are biased in moderate temperatures, while cooler temperatures have a female bias and hotter temperatures only produce females. In the article the males preferred a temperature of around 24.5 degrees Celsius. In the higher latitudes they have found that females made nests in very exposed locations which in turn would make the nest warmer. Another interesting fact they found was that at warmer locations embryogenesis was much faster so females would often pick higher latitudes to lay their eggs. Therefore the study found a tradeoff in the balancing of the male sex ratios with the speed of embryogenesis. This is especially troubling because when we consider how global warming could effect the sex ratios in these snapping turtle populations.
Source article: https://www.cambridge.org/core/journals/journal-of-zoology/article/geographic-variation-in-the-pattern-of-temperaturedependent-sex-determination-in-the-american-snapping-turtle-chelydra-serpentina/53B0514E374F3EA8E8488A90AB0A38B1#fndtn-information
2 comments:
I think it's really interesting to see research related to what we've learned in lecture. I hope that there will be more research on this topic in the future because it will become more and more of an issue with global warming and population decline. The fact about female turtles laying there eggs at higher elevations is super fascinating - it shows how adaptive and smart organisms can be!
Interesting study! How can females select their latitude? Nice photos!
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