ZOO-ology: Monarch day camp scheduled for kids
Oct. 2, 2011 at 5:02 a.m.
By Judie Farnsworth
The orange, black and white monarch butterfly may be the best known of all our butterflies.
They've started winging their way to Mexico or Southern California to escape winter weather.
Monarchs east of the Rockies migrate to Mexico and hibernate in oyamel fir trees.
Monarchs west of the Rockies hibernate in eucalyptus trees around Pacific Grove, Calif. Their long distance migration (some from Canada) is unmatched in the insect world.
The migration north takes in four generations in one year and each generation has a four part life cycle: egg, larvae (caterpillar), pupa (chrysalis), and the adult butterfly.
Their amazing journey is rather like a four-stage relay race. Fourth-generation great-great-great grandchildren butterflies travel the last leg - thousands of miles south to finish the journey. They form hibernation colonies in the same trees their first generation descendants used - even though they've never been there before. Pretty astounding.
Let's start from the gardens at The Texas Zoo in Victoria. Most autumn monarchs you see now are on their way to the mountains of Central Mexico. They are in stage four of their life cycle and are fourth-generation monarchs. They travel about 50 miles a day taking nectar from flowers. It appears that an internal biological compass acts with the orbit of the sun, enabling them to find their way even on cloudy days.
Fourth-generation monarchs have the longest life span (six to eight months) including the approximate two-month journey south and the over-wintering hibernation.
Hibernation is from mid-November to mid-February. When temperatures rise and humidity lessens, they come down from the mountains to mate. They begin migrating north and east, searching for milkweed plants where they will lay their eggs and soon die. This is life cycle stage one - generation one.
In March and April the eggs hatch into yellow, black and white striped caterpillars (larvae) that grow for about two weeks as they munch milkweed. Stage two - generation one.
A caterpillar attaches to a stem and forms a silky chrysalis (pupa). For the next 10 days a transformation (metamorphosis) takes place as the caterpillar becomes a butterfly. Stage three - generation one.
A lovely monarch butterfly emerges from its chrysalis. Stage four - generation one.
The monarch butterfly flies away, feeds on flowers and lives only about two to six weeks. It finds milkweed and dies after laying eggs for stage one - generation two.
And so it continues to the fourth stage of the fourth generation. This prolonged butterfly stage includes the incredible journey back to where it all began.
Milkweed doesn't grow in monarch over wintering areas, so they must migrate north to areas rich in this plant to lay their eggs. Their caterpillars eat it exclusively. It's not a plant most of us relish, but designating even a small area or unused field to the plant will help these butterflies that are losing their means of survival with habitat destruction.
Adult butterflies love fruit- bearing trees and lots of flowers. Try putting out some soft bananas or oranges. There are butterfly feeders that can be purchased. It's not difficult to have a yard full of these beautiful butterflies.
Treat your third- and fourth-graders to Monarch Madness Day Camp at The Texas Zoo from 1 to 4 p.m. Oct. 8. Pre-registration is required and can be done over the phone, call the Zoo at 361-573-7681.
Judie Farnsworth is a longtime volunteer at the Texas Zoo specializing in educational programs.