The Carlisle Mosquito Online

Friday, April 18, 2003


Spring Peeper
I have been watching for symbols of Easter and have not yet seen the Easter(n) Cottontail hopping down the bunny trail; and the gifts dropped in the woods by deer do not resemble easter eggs to me. I am reminded though of another favorite Easter food, the hot cross bun, by a version of the hare and the tortoise story (from a collection of 'Verse and Worse' by Arnold Silcock):

"A rabbit raced a turtle;
You know the turtle won.
And Mr. Bunny came in late;
A little hot cross bun!"

This brings me (of course!) to the Spring Peeper, the little tree frog that has a cross on its back.

Name: Spring Peeper or Pseudacris crucifer, a member of the tree-frog family, Hylidae. In older reference books you will find it classified in the genus Hyla along with the gray treefrog. It is now assigned to the genus Pseudacris, the chorus frogs.

When and where seen: Spring peepers can be seen in forested wetlands, wet meadows and bogs, but only by the very determined. Their presence is made known by the chorus of mating calls which can carry up to a quarter of a mile. I have been hearing them at the swamp on School Street for about 3 weeks.

Characteristics:. The spring peeper is a small frog the adult male is only an inch long and a large female about an inch and a half. They range in color from light to dark brown and usually have a darker colored X on their backs, and hence the species name crucifer. Sometimes, as with the specimen in the photo, the X is incomplete. Spring peepers have rounded pads on their toes which is characteristic of all members of the Hylidae family. They have little to no webbing between the toes.

Life Cycle: The tiny eggs (about 0.06 inches diameter) are laid singly or in clusters from early spring on into summer. One female peeper may lay as many as 800 eggs. The eggs hatch into tadpoles in 7 to 10 days. The tadpoles metamorphose into frogs in 5 to 8 weeks. Unlike most frogs, peepers still have a tail when they first emerge from the pond. It is lost as they complete their metamorphosis ashore. The rest of the year, adult peepers live in the leaf-litter in woodlands and only rarely attempt to demonstrate their treefrog affiliation by climbing 2 or 3 feet off the ground into a small tree or shrub.

Antifreeze: Spring peepers are subject to freezing temperatures in the winter (and in the spring some years!) and are able to limit the damage done by using glucose as an antifreeze agent.

Word of the day: Poikilothermous, having a body temperature that varies with the temperature of the environment, like peepers.

References: Thomas F. Tyning, Stokes Nature Guides, Guide to Amphibians and Reptiles; Leo P. Kenney and Matthew R. Burne, A Field Guide to the Animals of Vernal Pools.

Anyone can write the Biodiversity corner about any living thing, animal or vegetable, that exists in the wild and was seen in Carlisle. Or tell me what you've seen, or send me a photo, and I will write the column. Send the information to

2003 The Carlisle Mosquito