Nature Note – Frog Calls

Listen for the bullfrog’s “jug-o-rum” mating call in mid summer. Photo by TheBrit_2 via Flickr.

In early July gray tree frogs can still be heard calling for mates, but by the end of the month bullfrog (jug-o-rum) and green frog (like a single tong from a banjo string) calls become more prominent. Tree frogs breed earlier in the season because they utilize vernal pools for laying eggs. The advantage of vernal pools is that they hold fewer predators. The disadvantage is that the eggs must hatch and the tadpoles mature before the pools dry up. In contrast bullfrog and green frog tadpoles breed in permanent bodies of water. Their tadpoles will spend at least one winter in the water before maturing.