Geographic variation in incubation temperatures promoting viable offspring production in broadly co-distributed turtles.

Organisms whose early life stages are environmentally sensitive produce offspring within a relatively narrow range of suitable abiotic conditions. In reptiles, development rate and survival are often maximized if incubation temperatures remain under 31°C, though this upper bound may vary within and among species. We addressed this expectation by comparing responses to egg incubation at 30°C versus 33°C in congeneric turtle species pairs with broad syntopic geographic distributions.