Watching the Migration in your Own NeighBorhood

In many places, you don’t have to go to Mexico or California to witness the migration. You may find yourself in the middle of it if you are aware of what to look for. During the southward migration, monarchs can be found in even the densest urban environments. Nicholas Wagerik, an amateur naturalist who studies wildlife in Central Park was recently quoted in the New York Times as saying "I noticed it in Manhattan, and in other places, people said it was just spectacular," he said. "Every flower in Brooklyn Heights had a monarch on it."

As days shorten in mid August and September, monarchs as far north as Canada begin their migration south. The movement isn’t abrupt, but occurs over a few weeks and has peaks and valleys as a series of waves pass through, with the first often being the largest. These waves are caused by variations in starting times, weather along the route that can create bunches, and laggards that reach adulthood after the migration begins.

We’re all familiar with the collective noun in the phrases "a pride of lions," or a "flock of geese" but what about butter- flies? One popular candidate is a "rabble or swarm of butter- flies," and an "army of caterpillars."

As the waves of monarchs pass through your area, you may see monarchs feeding on flowers or flying determinedly south or southwest. If you see more than you normally do you may well be experiencing a small piece of the great migration. A few years ago, while visiting a friend living on the 18th floor of a Chicago high rise apartment, we sat in the comfort of his living room watching hundreds of monarchs glide by on their way south. It was an amazing sight to behold. The numbers involved and the routes they follow vary, so in some years you may see more monarchs migrating and in other years none at all. If driving when you see them, slow down as much as possible. Butter-flies can often survive a collision with a slower moving car because they get caught in its airflow and never actually hit the car. If you do see the migration you should start investigating where the monarchs are pausing for nectar or roosting at night. If you can find a tree they roost in, you’ll see a mini version of what the clusters in the overwintering areas look like.

To increase your odds of seeing the migration, start by checking the daily weather reports, especially for approaching cold fronts from the north and warm clear skies. On any given day some luck is involved even if you are on their migration route. Strong winds or winds from the south or southwest may keep them grounded and on very favorable days they may skip over your area entirely as they ride the winds high above. Check the Internet to see if there is a group in your area that reports on the migration and roosting areas. Most states and local areas have a site where people exchange timely information of this kind. Monarchs seem hesitant to cross wide bodies of water— such as the great lakes or Chesapeake Bay— so tend to buildup at beaches and shorelines waiting for good weather, especially on southerly peninsulas that funnel them to a point. These are good places to look as are places along the coast where they get crowded together in greater numbers.