Butterflies in NJ are About to Make a 2,000-mile Trip to Mexico
Fall is the time of year when you can see a fair number of monarch and some other species of butterflies migrating southward for the winter.
Mark Garland, director of the Cape May Monarch Monitoring Project, says they are flying to Mexico.
"The monarch butterfly, unlike most of our butterflies, has no adaptation that allows it to survive the prolonged freezes of winter in any of its life stages," Garland said.
"It needs to be in the temperate zone where winter occurs to take advantage of the abundance of the food plans. Its caterpillars need milkweed. So over the years, they figured out a way to wait out the winter, to migrate down to Mexico, where they spend winter in dormancy in the cool climate up in the high mountains west of Mexico City."
He says you will see this migration all over New Jersey right now.
"Literally anywhere in the state, you can see them and they will often concentrate where there are big flower gardens with a lot of blooming flowers."
"A monarch butterfly is a pretty busy butterfly but it's still a butterfly. They weigh about half a gram, which is about the equivalent of a normal sized paper clip. And from Cape May to get down to Mexico it's about 2,000 miles in a straight line that any of them make. It is pretty remarkable and that it's been going on for years and years."
The 2,000 mile trip is followed by a breeding cycle for the butterflies and future generations will actually be the ones finding their way north next spring.
"The ones we're seeing now, they won't meet until after they've gone through their period of dormancy. They typically make it back just to the southern tier of the United States to lay their eggs. Their offspring spread throughout the continent as far north as milkweed grows, which is sort of the southern hundred miles of Canada. And with each generation they're spreading out a little bit more. We tend to see monarchs in New Jersey the second and third and fourth generation."