i'd already researched monarch butterflies and was suitably impressed with how far they could migrate, so i wanted to research other really impressive migrations and came across dragonfly migration specifically the species green darner, they migrate far greater distances than the monarchs which i thought warranted some further exploration.
Dragonfly
migration stretches between 14000 and 1800 kilometers.
Migration
takes place in large swarms. In the swarm there is no actual leader, just many
of the same insect traveling together.
One
of the interesting features of dragonfly migration is that it seems to follow
the passage of cold fronts. It has been noted that even in two separate
geographic areas, two separate swarms of dragonflies began to migrate in
response to the same cold front.
The migratory patterns and apparent decision rules of green darners are strikingly similar to those proposed for songbirds, Migrating Green Darners have even been recorded in the Gulf of Mexico on oil platforms.Green darners do not fly until all fat reserves are used, but rather fly for shorter times ensuring continuous fat availability even after migratory flights.
Dragonflies, have difficulty being active when the air temperatures are cold. The Green Darner, however, can shiver its wings and the large flight muscles in its thorax produce so much heat that the insect's temperature may rise to 110 degrees Fahrenheit.
This very large dragonfly has two different strategies for surviving Minnesota winters. Some common green darners migrate south, just as many birds do. Once in the south, they breed, lay eggs, and then die. Their young then hatch and migrate back to the upper Midwest in spring. Their second strategy is to lay their eggs in the north, and have their larvae spend the winter beneath the ice of our frozen ponds. They then emerge in spring.
No comments:
Post a Comment