Thursday, May 1, 2008

Frogs & Butterflies

Nature WatchMay 1, 2008

By Susan Benson,
CNHM Director of Education

Although snow seems to want to stay, there are still many signs that tell us winter is coming to an end. Really! The loud, peeping chorus of spring peepers was heard last week. These frogs are among the very first to call and breed in the spring, often beginning when there is still ice on our lakes and snow on the ground. These frogs are found in temporary (vernal) spring ponds, or permanent ponds, marshes and ditches; following the breeding season they move into woodlands or fields. Peepers are easier to identify because they call out their name – peep, peep, peep. Sometimes peepers call while sitting under grass clumps or in crevices in the earth, allowing them to amplify their call; this technique also makes it difficult to track exactly from where the sound is coming. Other frogs to keep your ears out for include the western chorus frog that sounds like a person’s thumb pulling down a comb; the wood frog is said to sound a little like a squeaky duck quacking.

Last week’s warmth brought out a lot of butterflies. One of the most common during the warm spring days is the mourning cloak, black with yellow on the edges. These insects hibernate as adults, secreting natural antifreezes such as sorbitol into their bodies as the weather cools. They then find shelter under loose bark, in debris, or in a crevice under a roof overhang. Now, in the spring, mourning cloaks are the first to come out as their dark colors experience solar heating. Their spring food includes mostly tree sap, especially that of oaks. They walk down the trunk to the sap and feed head downward. Males will bask in the spring sun awaiting receptive females. Eggs are laid in groups circling twigs of the host plant. Caterpillars live in a communal web and feed together on young leaves, then pupate and emerge as adults in June or July. Due to their hibernation, the mourning cloak has a greatly extended adult span. While a period of about two weeks is a typical life span for most adult butterflies, mourning cloak adults live for up to eleven months. Other butterflies to keep an eye out for include the Milbert’s tortoise shell, red admirals, and the small blue spring azure.

Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 43570 Kavanaugh Street or on the web at to learn more about exhibits and programs.

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