Back to Nature: When Peepers Call, Spring Has Sprung
By Kathy Reshetiloff
Spring. Many people refer to their calendar for the first day of spring. Others look for crocuses blooming or first robin sighted. But for me, I know that spring has finally arrived the first time I hear spring peepers ( Pseudacris crucifer ) calling from a small patch of wet woods near my house.
Tiny frogs only 3/4 to 1-1/2 inches in length, spring peepers are one of the earliest frogs to call for their mates. Their call, a high-pitched ascending whistle like the sound of jingle bells, can sometimes be heard up to a one half a mile away.
Peeper breeding actually follows the wood frog ( Rana sylvatica ) by a week or two. However, its unmistakable mating call and large range make the spring peeper one of the most familiar frogs in North America. Spring peepers can be found from Manitoba to the Maritime Province in Canada, south through central Florida and west to Texas.
Throughout the Northeast, spring rains create temporary pools in woodlands and meadows known as vernal pools. M ale peepers converge on these moist breeding grounds. These ponds may last a few days or a few weeks but are critical to the life cycle of peepers and other amphibians including other frogs, toads, and salamanders.
The Greek word amphibious literally means creatures with a double life. Spring peepers begin their lives as an aquatic animal (living in water) and slowly change into a terrestrial animal (living on land).
All frogs produce sound by moving air back and forth over their vocal cords, making them vibrate. So although you may not see them, you can identify frogs and toads by their calls.
Peepers also have vocal sacs near their throats that the male inflate, helping to resonate their calls. Peeping reaches crescendo on warmest night and almost ceases if temperature drops below 30 degrees Fahrenheit.
Other common amphibians
- Wood frogs (Rana sylvatica) migrate to vernal pools early in the spring. Their call is a hoarse clacking sound, reminiscent of a quack.
- The American toad (Bufo americanus) ranges from mountains to backyards. Despite their warty appearance, their mating call is a pleasant musical trill.
- The marbled salamander (Amystoma opacum) begins breeding in fall, migrating to pools and depositing eggs. The larvae overwinter in the pool.
What you can do to preserve peepers and other amphibians: - Conserve water and energy.
- Replace exotic landscaping plants with native plants.
- Wash cars on grassy surfaces or at car washes that recycles wash water.
- Reduce or eliminate the nutrients, pesticides and herbicides on lawns and gardens.
- Join a watershed group or other organization dedicated to conserving habitat.
|
When ready, the females arrive and choose their mates. Mating occurs in shallow pools. The male sits on the female's back and fertilizes the 800–1,300 eggs she deposits. Once breeding is complete, peepers return to trees.
After two or three weeks, eggs hatch and tadpoles, less than 1/5 of an inch in length, emerge. Tadpoles are herbivores. They feed by inhaling water and filtering out blue-green algae. One ounce of tadpoles can clean 12 gallons of water every day.
In five months tadpoles metamorphose (change) into the adult form. Gills are replaced with lungs, legs grow, and tails are reabsorbed into the body. Adult frogs are carnivores, so their mouths become larger in order to eat other animals, manly insects. Peepers, in turn, are food for birds and small mammals
The new tiny frogs leave the water for their woodland habitat, continuing to grow and mature. Well developed adhesive disks on their toes make peepers expert tree climbers.
During the fall, peepers sometimes call. This is known as the fall echo. Scientists speculate that light and temperature conditions, similar to those in the spring, stimulate them to peep. Spring peepers hibernate during winter on land under logs and bark. A high concentration of sugar in the blood helps them survive harsh winter temperatures.
All across the country there has been a drastic decline in many amphibians including frogs, toads, and salamanders. Loss of critical forested wetland habitat seems to be the main cause. Many amphibians return to the same ponds and wetlands in which they were born to breed. If these natal areas are disturbed or gone, those amphibians will not breed. Woodlands also are needed as habitat for adult amphibians.
Protecting forested wetlands and woodlands is the first step to preserving amphibian populations. Rivers and their floodplains provide excellent corridors that connect isolated or fragmented woodlands.
Why should we care? Amphibians help us to measure the health of the environment. Because they exchange water and air primarily through their skin, they also absorb pollutants. Like a canary in a coalmine, a decline in local populations may indicate a contaminant problem.
Protecting woodlands, wetlands, and river corridors not only helps spring peepers, but also reduces the amount of nutrients and sediment entering rivers and the Bay. Plus in our increasingly concrete world, we all need a place to retreat. The peepers’ forests offer us such a haven, a place to enjoy the serenades from the woods.
Kathy Reshetiloff grew up in the Annapolis area. In 1988, she began working as a biologist for the U.S. Fish and Wildlife Service. Then, in 2000, she began her career as a writer, bringing wildlife and nature to her readers. She also writes a column, Bay Naturalist, for the Bay Journal newspaper published by the Alliance for the Chesapeake Bay. Kathy loves the outdoors and enjoys hiking, camping, paddling and diving. She recently finished hiking the entire Appalachian Trail with her husband Greg.