Why do butterflies migrate?
In temperate climates butterflies migrate to exploit new resources as the summer processes. Alternatively, the butterflies emerged in the summer search for a temperate enough place to over winter; Vanessa atalanta or Red Admiral is known to do this. Occasionally a migrant will establish a colony and over the years it will become a resident specimen; with climatologic change that is known to happen. In the tropics where the season is not a factor, the butterflies migrate away to establish new colonies. Should they stay in the area where they emerged, their caterpillars would have too much competition of food and thus they would starve to death. So, they migrate for the interest of their progeny and this is the reason why most migration occurs. Top of the page 23. What can I do for the butterflies? If you have a garden, you can make it butterfly friendly. On this website youll find advice how to get started. Click the links to go to Create a Butterfly Garden Butterfly Gardening Tips Butt
Many theories have been put forward to explain what causes butterflies to migrate and most of them centre round the idea that migration occurs in response to unfavourable conditions such as lack of food, insufficient food of the right quality, overcrowding or the onset of winter. In some insects, such as houseflies, flight seems to be a simple response to the environment-there is a shortage of food so they fly away. In butterflies the long migratory flights are almost certainly brought about by environmental factors which act in anticipation of unfavourable conditions before they actually happen. These triggers, acting through the hormone system of the developing larvae, change the physiology of the next generation so that specifically migrant adults are produced. Systematic and quantitative information on butterfly migrations is scarce despite the many occasions when migrations have been observed. Individual marking (similar to ringing birds) is difficult. Small tags can be attached t
