During winters in THE UNITED STATES, many amphibians dive or burrow deep in order to avoid freezingbut not the wood frog. These fig-size croakers stay put aboveground because the water between their cells freezes, plus they spend the growing season in some sort of cryosleep.
When spring arrives, most wood frogs awaken from their icy slumber with a very important factor on the mind: sex. Males look for a pond or temporary vernal pool and call to females with sounds almost just like a quacking duck, says Dartmouth Colleges Ryan Calsbeek, a biology professor who studies amphibians sex lives. As more males interact, the cacophony of croaks could be heard through the entire forest.
Hearing the come-ons from the ponds around them, females hop toward the croaks they find most seductive. In a recently available study utilizing an advanced acoustic camera, Calsbeek determined that female wood frogs, like many humans, cant resist deep, husky voices. Such croaks have a tendency to result from large frogsbut once a lady is lured to a pond, shes fair game for several its male frogs, including small sopranos. The victor may be the male that grasps and mounts the feminine, wrapping his forelimbs around her torso, a posture referred to as amplexus. He squeezes until she deposits her eggs in to the water; then releases sperm, fertilizing the eggs.
Its female wood frogs fate to possess several breeding opportunities throughout their two-to-three-year life time. So it’s likely that good that theyll find a minumum of one big baritone daddy.
Lithobates sylvaticus will be the only amphibians found north of the Arctic Circle. In Canada, and also Alaska along with other parts of america, they reside in tundra, grassland, and forest habitats.
Wood frogs bodies create a type of natural antifreeze that prevents their cells from bursting because they ice over through the winter. The thumbs of males swell during breeding to greatly help them retain females.
This story appears in the October 2022 problem ofNational Geographicmagazine.