Exploring the web of life

Photograph by T.W. Davies of the California Academy of Sciences

Species of the Month:
Mourningcloak Butterfly

This velvety beauty is the first "flying flower" to appear every spring. Its scientific name, Nymphalis antiope, compares it to young and beautiful nymphs of Greek mythology. The name "Mourningcloak" refers to its resemblance to cloaks once worn by people in mourning. I, on the other hand, would have named it after a pansy!

• Why is this butterfly the first to "flutter by" every spring? While most other species hang out all winter as eggs, larvae, or pupae, Mourningcloaks are able to pass the winter as adults. They hole up in snug hideaways called "hibernaculums" in tree crevices, leaf litter, or even buildings.
• They secrete an "anti-freeze" chemical that prevents ice from forming in their tissues and stopping the flow the blood.
• Butterflies have blood? Yup, but it's not red like ours because it doesn't carry oxygen. They get their oxygen through valves in their sides. It moves through their bodies in "air tunnels."
• Mourningcloaks emerge temporarily on warm winter days, but you'll rarely see one before January 25, according to U.C. Davis butterfly expert Arthur Shapiro.
• Most butterflies live only 2 weeks, so the Mourningcloaks we see in early spring are ancients – survivors from the previous year. Some live to the ripe old age of 10 ––– months, that is!
• Mourningcloaks drink nectar through long, double-barreled feeding tubes, including the nectar of Toyon flowers (see last column). But they prefer tree sap, especially from oak trees. The sap oozes from wounds in the tree or from holes made by woodpeckers. They also drink the liquid in dung and mud.
• Like other butterflies, Mourningcloaks aren't major pollinators. Pollen doesn't stick to their legs for transfer to other flowers as it does with bees, the primary pollinators.

• Mourningcloaks lay their eggs in the spring on twigs of willow, cottonwood, and California Buckeye. Look for a mass of eggs that completely encircles a twig.
• After the eggs hatch, the caterpillars remain in a cluster, unlike other caterpillars. When disturbed they thrash and vibrate as a group to frighten potential predators. That would be fun to see!
• Butterflies must be warm to fly, which is why you often
find them basking in the sun. Most spring butterflies such as Mourningcloaks have dark bodies, the better to absorb
sunlight.
• Listen for a sharp clicking sound from a Mourningcloak as it takes to the air. That means it has been disturbed.
• Along with many other California butterflies, Mourningcloak populations declined dramatically in 2006 due to unusual weather patterns. Mourningcloaks are also sensitive to pesticides and loss of their larval host trees (see above).
• Butterflies are at the bottom of the animal food chain. The eggs, larvae, pupae, and adults become food for numerous insects, amphibians, reptiles, birds, and mammals. We can help the entire food chain by protecting and nurturing our lovely "winged pansies."

Exploring the Web of Life© is a monthly column written by Kate Marianchild of Ukiah, CA, with help from her friends.