Monarch butterflies that migrate have the average lifespan of 6-8 months, whereas the average lifespan of a monarch that does not migrate is 6-8 weeks.
Monarch butterflies are known for the incredible mass migration that brings millions of them to California and Mexico each winter. North American monarchs are the only butterflies that make such a massive journey up to 3000 miles. The insects must begin this journey each fall a head of winter which will kill them if they tarry too long.
Butterflies that emerge from the chrysalides in the late summer and early fall are different to the ones that do so during the longer and warmer days of summer. These monarchs are born to fly and know they must prepare because of the lengthy journey.
only monarchs born in late summer or early fall make the migration, and they make only one round trip by the time next years winter migration begins at least 3 summer generations will have lived and died and it will be the last years migrators great grandchildren that make the trip. These generations somehow know they way, they follow the same routes and even return to the same tree.
http://www.travelswithtwo.com/wp-content/uploads/2008/06/monarchcluster01.jpg
Monarch butterflies can fly
in still air at a speed of around 50 kilometres (30 miles) per hour, and
considerably faster with a tail wind. They usually fly close to the ground, but
have been found as high as 3,500 metres (12,000 feet).1 They have been known to
fly more than 600 kilometres (375 miles) over water non-stop in 16 hours.
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_9FPF_k4qaIBwtrOjzhDUwgCETEGznZXBO7i_N6cTIX4Abh7xbkhzTwSaREQnGUL6weHPZT0Dh4gRnBn_AeeSKIaY76VgbUWQteBWwN4NQ7Ggu4w3nGDfq3cZLeK49seHgC2bhkGGR_Q/s1600/monarch-butterflies-mexico_28112_990x742.jpg
Monarch butterflies know fall
is here the same way that we do; they feel the chill in the air. While we adapt
by putting on a sweater, the situation is much more serious for the monarchs.
Temperatures below 55°F make it impossible for them to fly; temperatures below
40°F paralyze them. The monarchs originated in the tropics and can't live for
long at temperatures below freezing.
At the same time that the air
is cooling, the nectar supply that feeds the butterflies is dwindling. To
survive, the insects begin migrating in late summer, flying with the wind to
reach their winter homes.
Up to 100 million monarch
butterflies migrate either to California or to Mexico each year. (This isn't
the entire population. Some monarchs never make the migration.) There are more
than 25 winter roosting sites along the Californian coast and about a dozen
known sites in the Sierra Madre Oriental Mountains of Mexico. In both regions,
butterflies depend upon trees for their survival. The insects cluster in pine
and eucalyptus trees along the California coast and in ovamel trees in Mexico.
Wintering monarchs cluster together.
The end result looks like massive clumps of feathery orange-and-black grapes.
Each butterfly hangs with its wings over the butterfly beneath it, creating a
shingle effect that buffers the bugs from the rain and creates warmth. The
weight of the cluster also prevents the butterflies from being blown away.
Butterflies stay in their
winter homes until about March, when they begin a quick retreat to their summer
homes, at times traveling as fast as 30 mph.
http://www.worldofstock.com/slides/OAC2053.jpg
i found some very high quality photographs of monarch butterflies which i thought could be useful as possible background for my pages- i also have a video from a david attenborough documentary that explains and displays the process of monarch butterfly migration which i have cut down to the monarch section and plan to integrate into my page. ideally i think id like to keep the monarch section to one but i have enough for two so it depends on the other animal migrations i focus on.
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