How does the size of Wood Frogs typically vary between the northern and southern portions of their range?

Frogs in the colder, more northern reaches tend to be smaller than those in warmer, southern portions.

The wood frog exhibits clinal variation across its vast geographic distribution, which spans from the southeastern US up into the boreal forests of Alaska and Canada. This variation is directly correlated with temperature regimes across latitude. Specifically, individuals found in the colder, northern latitudes of their territory generally tend to be smaller in physical size compared to their counterparts residing in the warmer, southern regions of their range. This pattern illustrates an ecological adaptation, potentially linked to differing thermal constraints or variations in the length of the food availability window throughout the year across this broad north-south expanse.