The Monarch Butterfly Story

foreign [Applause] [Music] places The Sight and Sound of migrating birds is a familiar sign of fall but did you know that even some insects migrate each year 's one the monarch butterfly during August and September swarms of monarchs begin their fall migration to warmer Southern lands how can you study the migratory root of a butterfly one way is to catch and then tag the butterflies a small adhesive label applied to One Wing indicates where the insect was first found further south if the tagged butterfly is captured again the route it traveled can be mapped migration can be dangerous along the way predators take their toll but monarchs do have some protection if a young Monarch has eaten certain types of plants it becomes poisonous to predatory Birds a bird choosing to Feast on the wrong butterfly will become sick and the experience will usually teach it to avoid eating monarchs monarchs often use trees and bushes as overnight roosting sites in fact there are traditional stopping points that they use year after year during the peak of migration monarchs cling to the branches of these roosts by the thousands unlike Birds monarchs do not travel along migratory routes or flyways as summer ends most monarchs migrate to isolated locations in central Mexico and along the coast of California where they spend the winter come spring the butterflies begin the return trip North and during this journey they go through several Generations you see unlike Birds the individuals that fly south in the fall are not the same individuals that repopulate North America in Spring the monarchs that spread across the continent in Spring are actually the great great grandchildren of the Fall migrants during the long flight the monarchs feed on the nectar of spring flowers and females lay their eggs on milkweed plants because of the close association between the plant and the Butterfly some call the Monarch the milkweed butterfly monarchs and other butterflies belong to the group of insects called lepidoptera lepidoptera means Wings covered by scales and that's a good description because the colored powder that coats a butterfly's Wings is really thousands of tiny scale-like plates a close-up look shows the scales arranged in a pattern of even rows all lepidoptera undergo complete metamorphosis this means that their life cycle has four distinct stages they start as an egg then become a larva or caterpillar then a pupa or chrysalis and finally an adult after mating the female Monarch lays a single egg on the leaf of a milkweed plant in two to four days the caterpillar hatches the caterpillar has a tremendous appetite and eats milkweed leaves nearly Non-Stop it grows very quickly and in only two weeks the caterpillar's weight increases 2 000 fold just look at the difference in size in fact The larva is gaining weight so fast its skin cannot stretch enough to keep up and so periodically it sheds its old skin in a process called molting the caterpillar crawls about on five pairs of fleshy limbs called pro-legs as it moves over the surface it lays down a sticky thread of silk that it spins from its mouth small hooks on the pro legs snag the thread and hold the caterpillar on track after about two weeks the caterpillar has grown to its maximum size it stops eating and begins to search for a resting place here it will take the next step in Metamorphosis the change from Caterpillar to pupa once it is found a protected spot the caterpillar spins a layer of silk on the surface slowly it weaves the silk into a kind of button the caterpillar then reverses its position and grasps the silk button with its back pair of pro-legs the hooks on the pro legs become entangled in the silk mat and the caterpillar hangs upside down clinging to the silk button within 8 to 12 hours The larva begins to swell the outer skin splits and is pushed off the body revealing what will become the pupa next a barbed outgrowth called the creemaster is pulled from underneath the larval skin and is pressed firmly into the silk button the pupa gyrates and eventually the crumbled larval skin drops away slowly the pupa case becomes firmer and smoother and gradually the pupa within takes on a dark green color soon however the bright orange and black markings of the adult Monarch appear through the transparent pupil skin finally the pupa case splits open and metamorphosis is complete the wings of the new butterfly that emerges are soft and limp as it dries in the air the butterfly pumps body fluid into its wings to expand them after a few hours the fluid dries and wings are stiffened and ready for flight in just over a week the Monarch has passed through its pupa stage and has gone from crawling caterpillar to flying butterfly now the cycle will start again and a new generation of monarchs will live the four roles that make up the life of a lepidoptera [Music] [Music] [Music]