An incredible journey: the monarch butterfly
Wednesday, October 20, 2010
Media contact: Jessica Basham
As summer fades into fall, the days grow shorter
and the evenings turn cooler, but there is a bright spot fluttering
in the air. It is the monarch butterfly in the midst of its amazing
annual migration south.
The migration fascinates scientists and other
nature-watchers. How can a seemingly delicate butterfly make
a 2,500-mile journey across the United States, the Gulf of Mexico
and into central Mexico? And how does it, and its thousands
of companions, know where to go and how to get there?
First, let's look at the monarch's life
cycle. A monarch butterfly begins life as an egg, a tiny dot
laid on the underside of a leaf. During its second stage of life,
the larval stage or caterpillar, it feeds on its favorite food
plant, milkweed, and grows quickly.
Its pupa stage, or chrysalis, is the stage where it
transforms (metamorphoses) into an adult, the recognizable
orange-and-black butterfly we know as the monarch. What
happens next depends on what time of year the adult emerges.
Adult monarchs that emerge in spring or early
summer enjoy a fairly typical butterfly lifespan of 2-5 weeks,
during which they feed, mate, lay eggs and die. However,
monarchs that emerge in the late summer have more on their agenda -
migration! These special monarchs may live 7-8 months, making
them the longest-lived butterflies.
Once they reach Mexico in November, the monarchs
roost by the hundreds of thousands on oyamel fir trees.
There, they hibernate until March before starting a northward
migration. Then, they mate, lay eggs and die. Their
offspring continue the journey north through the spring and
summer. It takes four generations of monarchs to reach the
northern United States and southern Canada. It is the offspring of
this last group who are destined to repeat the southward migration
of their great-great-grandparents. Monarchs are the only insects
that have such an incredible migration.
Fall is the best time to see butterflies in North
Florida, and mid-October to mid-November is the peak time to see
them. You can see monarchs feeding in clusters on goldenrod,
saltbush and other wildflowers, especially along the coast.
For more information about monarch butterflies and
their migration, visit www.ifas.ufl.edu and type "monarch butterfly"
in the search box. The www.monarchwatch.org site has wonderful
information as well.
Also, St. Marks National Wildlife Refuge in North
Florida celebrates an annual festival dedicated to the monarch
butterfly. This year it is on Saturday, Oct. 23. This
is a wonderful time to Get Outdoors Florida! and take your family,
students and friends to a wonderful, educational event. Visit www.stmarksrefuge.org/calendar.cfm for more