Dry as a desert wind, a blast of hot air whooshed out of the log garage as I lifted the door. Immediately I spotted a butterfly battering the window glass. It had been several days since I had been in the garage, so I wondered how long it had struggled to escape.
Thinking it must be dehydrated, I carried it to the birdbath. Gently, so as not to harm its wings, I placed butterfly on the rim and waited to see if it would drink. Within seconds, its proboscis unfurled and began to suck up water.
Once hydrated, I gave the Compton Tortoiseshell some food so it would recover. In the house I concocted a mixture of sugar and water and placed it on a cover from a can of chocolate syrup. Returning to the birdbath, I delicately moved the butterfly to the lid filled with sugar water and then proceeded to get on with my chores while occasionally checking on its progress.
After some time it lifted off. I cheered. When it alighted on the ground and closed its wings I was fascinated by its cryptic coloration. It looked like a piece of tree bark lying on the ground. Had I not seen it land I would have walked by without noticing it.
Intrigued by the encounter, I wanted to learn more about this beautiful butterfly.
More than 6,000 species of butterflies are found worldwide and about 700 live in North America. Some field guides provide so much information they are overwhelming. I turned to a wonderful regional resource, "Butterflies of the North Woods" by Larry Weber.
Identifying the Compton Tortoiseshell was easy. According to Weber, the butterfly was named after Compton County, Quebec and for the brown-yellow wing pattern that resembles the mottled appearance of the hawksbill turtle. Its wings have several black spots and are rusty brown near the body. One white spot appears on all four wings. This diagnostic field mark distinguishes it from a similar species such as the smaller Gray Comma, which doesn't have white spots.
Compton Tortoiseshells hibernate beneath tree bark and in hollow trees. They use buildings as hibernaculums as well. One observer noted 30 sheltered butterflies tucked behind a window shutter.When in danger they close their wings, allowing their camouflaged undersides to blend with tree bark.
Adults emerge and mate in early spring to have one brood each summer. They lay eggs on aspens, birches and willows. Caterpillars, which eat the leaves of their birth host plant, are light green with black spines. The horned-headed, brown-green chrysalis hangs from wood.
Tree sap, especially maple, and rotting fruit make up the majority of the menu for adults. Moisture and nutrients are also taken from damp soil and dung.
Look for Comptons in a variety of wooded sites, including forest openings, edges and trails. They prefer upland boreal forests, especially mature deciduous trees, of which I have an abundance.
The next two months will be ideal for discovering the winged wonders of the insect world. Take time to get acquainted with these beauties.
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