By late April, American toads dig themselves out of the soil where they hibernated and head for ponds and marshes. Like all amphibians, they must lay their eggs in water. While sitting in shallow water, the male makes its loud, trilling mating song with its vocal cords. Its puffed-out throat sac helps amplify the call. Each trill is high-pitched, has a whistle quality, continues on the same notes and is maintained uninterruptedly for about 20 seconds. The staff naturalists at Lowry Nature Center, in Carver Park Reserve located near Victoria, alerted me to the American toad call 45 years ago when I started working as an outdoor education teacher. I have looked forward to hearing this sound of spring since.

You won't get warts on your hands from picking up a toad, but you will learn something about this remarkable amphibian. It feels cold to the hand because it's a cold-blooded animal, which means an animal with blood the temperature of its surroundings. When first evolved (leaving the water from the tadpole state), it is only about a half-inch long, but an adult grows to nearly four inches.

Females arrive in the breeding ponds a few days after the singing males and lay strands of eggs, which are fertilized by males. Toad eggs hatch in two to a dozen days.

Jim Gilbert's Nature Notes are heard on WCCO Radio at 7:15 a.m. Sundays.