Clark Gardens 092511 1010
Across the USA monarchs soar and glide in the warm sunshine from March through October (depending where they are born), but what happens in the fall when the brisk cold winds set in and winter looms in the air? Monarchs cannot survive cold winter temperatures of the northern states. So what does a monarch do to keep warm? It MIGRATES south and HIBERNATES! This means that it rests, with a very slow heart rate, just like bears in their hibernation caves. Monarchs east of the Rockies migrate 2500 miles to the Oyamel fir trees of Mexico. Monarchs west of the Rockies migrate to southern California to the eucalyptus trees of Pacific Grove and surrounding areas.
The monarch's flight to Mexico has been compared to the migration habits of birds flying south for the winter. It is the only insect that can fly 2,500 miles to a warmer climate. Their unique wing structure and yearly life cycle makes it possible for the fall generation monarchs to travel thousands of miles (on those amazing little wings) to the warm nesting grounds of Mexico and southern California.
(www.monarchbutterflyusa.com/Migration.htm)
When the late summer and early fall Monarchs emerge from their pupae, or chrysalides, they are biologically and behaviorally different from those emerging in the summer. The shorter days and cooler air of late summer trigger changes. In Minnesota this occurs around the end of August. Even though these butterflies look like summer adults, they won't mate or lay eggs until the following spring. Instead, their small bodies prepare for a strenuous flight. Otherwise solitary animals, they often cluster at night while moving ever southward. If they linger too long, they won't be able to make the journey; because they are cold-blooded, they are unable to fly in cold weather.
Fat, stored in the abdomen, is a critical element of their survival for the winter. This fat not only fuels their flight of one to three thousand miles, but must last until the next spring when they begin the flight back north. As they migrate southwards, Monarchs stop to nectar, and they actually gain weight during the trip! Some researchers think that Monarchs conserve their "fuel" in flight by gliding on air currents as they travel south. This is an area of great interest for researchers; there are many unanswered questions about how these small organisms are able to travel so far.
Another unsolved mystery is how Monarchs find the overwintering sites each year. Somehow they know their way, even though the butterflies returning to Mexico or California each fall are the great-great-grandchildren of the butterflies that left the previous spring. No one knows exactly how their homing system works; it is another of the many unanswered questions in the butterfly world.
Clark Gardens 092511 1010
Across the USA monarchs soar and glide in the warm sunshine from March through October (depending where they are born), but what happens in the fall when the brisk cold winds set in and winter looms in the air? Monarchs cannot survive cold winter temperatures of the northern states. So what does a monarch do to keep warm? It MIGRATES south and HIBERNATES! This means that it rests, with a very slow heart rate, just like bears in their hibernation caves. Monarchs east of the Rockies migrate 2500 miles to the Oyamel fir trees of Mexico. Monarchs west of the Rockies migrate to southern California to the eucalyptus trees of Pacific Grove and surrounding areas.
The monarch's flight to Mexico has been compared to the migration habits of birds flying south for the winter. It is the only insect that can fly 2,500 miles to a warmer climate. Their unique wing structure and yearly life cycle makes it possible for the fall generation monarchs to travel thousands of miles (on those amazing little wings) to the warm nesting grounds of Mexico and southern California.
(www.monarchbutterflyusa.com/Migration.htm)
When the late summer and early fall Monarchs emerge from their pupae, or chrysalides, they are biologically and behaviorally different from those emerging in the summer. The shorter days and cooler air of late summer trigger changes. In Minnesota this occurs around the end of August. Even though these butterflies look like summer adults, they won't mate or lay eggs until the following spring. Instead, their small bodies prepare for a strenuous flight. Otherwise solitary animals, they often cluster at night while moving ever southward. If they linger too long, they won't be able to make the journey; because they are cold-blooded, they are unable to fly in cold weather.
Fat, stored in the abdomen, is a critical element of their survival for the winter. This fat not only fuels their flight of one to three thousand miles, but must last until the next spring when they begin the flight back north. As they migrate southwards, Monarchs stop to nectar, and they actually gain weight during the trip! Some researchers think that Monarchs conserve their "fuel" in flight by gliding on air currents as they travel south. This is an area of great interest for researchers; there are many unanswered questions about how these small organisms are able to travel so far.
Another unsolved mystery is how Monarchs find the overwintering sites each year. Somehow they know their way, even though the butterflies returning to Mexico or California each fall are the great-great-grandchildren of the butterflies that left the previous spring. No one knows exactly how their homing system works; it is another of the many unanswered questions in the butterfly world.