Frog Migration During Mating Season

Winter

• Unlike most species of birds, frogs do not migrate to a warmer climate during cooler winter months. Instead frogs go into a semi-dormant state during the winter. When the temperature is at or below the freezing mark, frogs will find a spot, usually below water, to spend the winter. Some frogs burrow into the mud, while others simply sit on the floor of a pond or other body of water.

Spring

• As the weather begins to warm up in the spring, frogs begin to stir to life as they prepare for the mating season. Frogs become active even when spring temperatures are still cool. The actual timing of this will depend on the temperature and humidity as well as the species of frog.

Breeding Sites

• Once they awake from their winter dormancy, frogs migrate to their breeding sites. Most frogs do not travel far to reach these sites. Frogs usually migrate at night. Frogs seems to prefer to travel when it is raining at night, as during these periods they have been observed to travel greater distances. However, frogs will migrate during dry weather as well. The breeding sites will always be a body of water, usually a pond or a swampy area.

Mating Calls

• Once the frogs have migrated to the breeding sites, they will begin to make mating calls. The calls are made only by male frogs. These are usually the first frog sounds you will hear in the early spring. Because some frogs become active earlier in the season than others, you will likely first hear one variety of frog, followed later by other calls. The males make these calls to attract the female frogs to the breeding sites. Besides the mating calls, males may also make vocalizations to warn off other males. Both male and female frogs will make noises to warn of danger.

Breeding

• When breeding, female frogs will lay hundreds to thousands of eggs. These may be attached to aquatic plants or simply left floating on the surface of the water. Many of the eggs will be eaten by other species before they have a chance to develop and hatch. While the female is laying the eggs, the male attaches itself to the female's back to fertilize the eggs.

Post-Breeding Migration

• After breeding, many frogs migrate to their summer habitats. This is usually a pond or swampy area, but some species of frog, such as tree frogs can live away from bodies of water. The distance frogs travel to reach these summer habitats is not great, but will depend on the species, terrain and in some cases the sex of the frog. A 1995 study of Columbia spotted frogs found that males migrated to a summer habitats as far as 464 yards away, while females traveled as far as 1,130 yards from the breeding site.