Northern Leopard Frogs

There is another voice we should listen for this spring, the voice of the northern leopard frog. Named for their leopard-like spots they began singing or calling to attract mates in mid-March. Their mating season peaks in April and will continue through early June.  Their call has been described as a low, rumbling snore – like a thumb being rubbed over a ballon – with occasional clicks and croaks.  These guys can even sing when totally submerged in water!  During breeding season, you will find them in still waters such as marshy edges and banks alongside channels of streams and rivers, and in springs, wetlands, beaver ponds, and vernal pools.  While normally staying close to water, these frogs will venture farther from it when breeding season is done to hunt in meadows and grassland.  This is where they get their other often heard names – meadow frogs or grass frogs.  Found across the state, this frog is native to Ohio. In fact, northern leopard frogs are found across North America from Canada’s Northwest Territories to the US-Mexico border.

When they’re not breeding, leopard frogs are solitary and quiet.  Though they may scream loudly if caught by a predator.  And you may have heard a squawk and splash as one jumped into the water as you passed by.  When threatened, staying absolutely still, making erratic leaps or escaping to the water are its defensive moves.   They are primarily nocturnal but will hunt during the day.  About the size of a teacup, they are green or greenish brown with round brown/back spots on their back, sides and legs. The spots usually have a whitish or yellow boarder.  They have a light colored dorso-lateral fold that runs from each eye down the length of the back and a light-colored line that runs from the nose to each shoulder.  Their color, spots and lines help them disappear into their surroundings.  Leopard frogs are carnivores and they aren’t at all picky about what they eat.  They’ll eat bugs, snails, earthworms, other frogs – anything smaller than them that fits in their mouth.  They hunt by not moving, by being very still and waiting for prey to come close, then leaping forward and dragging its meal into its mouth with its long sticky tongue.

The northern leopard frog is a valuable member of their ecosystem. As predators, they keep their prey populations in check and in turn they are prey for a wide variety of animals.  But their most important role is as an indicator species.  They are particularly sensitive to environmental changes, and like all amphibians, they are important indicators of the health of their ecosystems.  Declining population numbers, changes in behavior or physical deformities are strong indicators of pollution or toxic substances in the environment.  All ecosystems are being increasingly exposed to artificial light at night.  Leopard frogs need the dark of night to breed, to eat, to hide from predators – to thrive.  Let’s help the northern leopard frog by turning off all unnecessary lights.