Spring comes a lot earlier than our calendars indicate. My first clue came March 2. Arriving home from the airport very late that night, I was greeted by a chorus of spring peepers, tiny frogs whose song sounds like sleigh bells.
Spring peepers live in the forest. Adhesive disks on their toes make them expert tree climbers. During their breeding period, from February to March, spring peepers leave the trees to mate in open water.
Temporary ponds formed by the periodic spring flooding of forests are the main breeding sites. Although these ponds may last only a few days or weeks, they are critical to the life cycle of many amphibians, including spring peepers.
Spring peeper breeding actually follows the wood frog by a week or two. But its unmistakable mating call and large geographic range make the spring peeper one of the most familiar frogs in North America. Spring peepers can be found from Manitoba to the Maritime Provinces in Canada, south through central Florida and west to Texas.
Spring peepers, like all frogs, toads and salamanders, are amphibians. Most amphibians lay soft eggs in water. The eggs hatch into larvae, in this case tadpoles, which are aquatic organisms. Most amphibians also go through an aquatic larval stage that looks and acts quite different from the adult.
As open water appears in early spring, male peepers converge on moist breeding grounds. Because they sing to attract females, only males “peep.” This mating call can sometimes be heard up to a half a mile away.
Peeping reaches a crescendo on the warmest night and almost ceases if the temperature drops below 30 degrees Fahrenheit.
Breeding areas are easily discovered, but finding these small frogs is difficult because they hide under aquatic vegetation.
When ready, females arrive and choose their mates. The male sits on the female’s back and fertilizes the 800-1,300 eggs she deposits. The eggs, only 1/200 of an inch long, are laid singly on underwater vegetation. Depositing the eggs can take about one day to accomplish. Once breeding is complete, peepers return to trees. The following spring, the cycle begins again.
Another key to spring’s arrival is the migration of fish. About a week after hearing my first peepers, I watched as dozens of fish tried to negotiate a small dam in Queen Anne’s County MD. Fish of all kinds were valiantly swimming against the current and artificial topography, trying to get upstream to spawn. Alewife, shad, perch and other fish filled the shallows until there seemed to be more fish than water.
The Chesapeake Bay watershed is like a highway system for fish. Many journey from the ocean to freshwater to spawn. These fish are known as anadromous, a word meaning “running uphill.” And these fish literally swim upriver against the flow of water.
The fish most famous for their spring runs are in the herring family: blueback herring, alewife, hickory shad and American shad. As adults, these fish inhabit offshore Atlantic waters. During the spring, they swim up the Chesapeake Bay to freshwater to spawn, usually returning to the same river in which they were born.
How they do this is a mystery. Many scientists believe this homing instinct may be due to an uncanny sense of smell and sensitivity to magnetic signals, polarized light and unique characteristics of the natal stream.
The onset of spawning is related to water temperature and length of day.
The spawning season for alewife generally runs from March through April. Blueback spawn from mid-April through late May. Shad spawn from March through June. Alewife favor slow-moving sections of streams while blueback herring prefer to spawn in swift water.
Upon reaching the spawning ground, males circle a lone female. As this mass of fish swirls around, the female releases her eggs and the males release their sperm. After spawning, the adults swim back downstream and return to the ocean.
Not to be overlooked at this time of year are the birds. I certainly could not overlook the flock of wild turkey that wandered into the woods of my backyard. Three males were vying for the attention of the 15 or so females milling about. When one male fanned out his tail feathers, puffed out his chest and strutted about in circles, the females quickly took notice and followed him as he flew to another wooded site.
The Chesapeake Bay watershed contains many different habitats that support this diverse collection of wildlife. However, it has been estimated that an acre of land is lost to development every six to 10 minutes. This translates into loss of food, cover and breeding areas for our wildlife.
Excessive sprawl and development also adds nutrients and other pollutants into our waterways.
To combat this trend, many federal and state agencies offer incentives to landowners to conserve or restore wetlands, forests and grasslands. Homeowners can help by creating small pockets of wildlife habitat in their backyards through BayScaping.
Every resident can also influence local land use decisions. Attend public hearings and meetings. Let elected officials know your views on conserving wildlife habitat.