Like all amphibians, toads breathe through their skin as well as with their lungs. When a toad is inactive the skin usually absorbs enough oxygen to meet its needs. During and after activity a toad often supplements its supply of oxygen by actively breathing air into its lungs. Unlike mammals, amphibians do not make regular and rhythmic breathing movements but bring air into their lungs spasmodically as the need arises. Air enters the toad’s mouth through its nostrils, and by raising the floor of its mouth, the toad forces the air into its lungs. (Photo is of an American Toad.)
Although Spring Peepers emerged from hibernation about two months ago, on warm nights the males are still advertising for mates and will continue to do so into June. Let your ears guide you to the peepers as they call repeatedly, often while perched on low vegetation near water. Armed with a flashlight, look for the movement of their vocal sacs as they inflate and deflate as the peepers sing.
Under the stealth of a rainy night, subterranean-dwelling spotted salamanders migrated to their ancestral breeding pools this week. Groups, or “congresses,” of males gather, followed by females. Once a female locates a congress of males, she eventually pairs up with one of them. The pair of salamanders then engages in a courtship dance ending with the male depositing a tiny white packet of sperm called a spermatophore on the bottom of the vernal pool. If he has sufficiently stimulated the female, she picks up this packet into her cloaca, or vent, and fertilization takes place. The next morning the only sign that spotted salamanders have been and gone are the unclaimed spermatophores scattered on the leaves that lie on the pool bottom.
After noticing the sudden loud clacking chorus at a nearby temporary woodland vernal pool, I went down to investigate, and there were dozens of wood frogs floating on the surface, as they croaked their duck-like quacks in the hopes of attracting female wood frogs. As far as I could determine, they were out of luck on this, their first day at the breeding pool, as I don’t believe the females have arrived yet. One clue was the relatively small size of the floating frogs and it seemed as though every frog was calling (only males call). Plus, time after time a wood frog would swim up to another wood frog and attempt to grasp it only to have the object of its desire utter a “release” chirp (a call made only when a male clasps another male) and swim rapidly away.
I heard my first peeper on March 18th, roughly two weeks earlier than in past years. These tiny members of the treefrog family begin mating rituals shortly after the end of hibernation. The males gather at small pools by the hundreds. Each male establishes a small territory and begins calling the familiar high-pitched “peep” quite frequently. The louder and faster he peeps, the better his chances are of attracting a receptive female. Males usually compete in trios, and the male with the lowest-pitched call usually starts the vocal competition. If you look closely at the peeper in the photograph you can see some snow fleas hitching a ride.
You may well have heard the single “peep” of a male spring peeper emanating from the woods recently. It does seem odd to hear this call now, often far from water, as we associate it with spring courtship. This phenomenon occurs so regularly in the fall that herpetologists have given it a name – “fall echo.” They speculate that peeper calling is spurred by light and temperature conditions, when fall climate conditions are similar to those of spring.