Posts tagged Kennebunk Plains

Monarch Butterfly Migration

Migrating Monarch Butterfly on a Northern Blazing Star plant (Kennebunk Plains, ME)

Migrating Monarch Butterfly on a Northern Blazing Star plant (Liatris scariosa on Kennebunk Plains, ME, which has 80% of the world’s population of this plant).

We had come to Maine for a day or two last week and I was treated to a front row seat on the Monarch Butterfly migration.   I was sitting watching the Northern Gannets through my scope as they performed their spectacular plunge dives into the ocean.  As I watched bird after bird crash into the sea, I became aware of Monarch Butterflies floating by, three or four a minute.  While most butterflies winter over in hibernation, Monarchs have evolved to migrate, more like birds than insects.  The excellent website Journey North has interactive maps to track the Monarch migration, and a check of the map showed me that the peak in Maine was occurring right in front of me.  The Maine birding list serve made note of this in a post from the edge of the Piscataqua River, relating how 500 or more of the butterflies had gathered at a spot on the shore of the river, waiting for more favorable winds before continuing.

These Monarchs I am seeing are thought to be the final generation of the year in the north and will travel as far as Mexico, overwinter there and travel halfway back next spring.  The migrating monarchs are different from the ones we see all summer as they have not reached sexual maturity.  This will happen next spring as they begin the trip north again.  It may take as many as five generations of Monarchs to reach maturity over the next summer before the migration begins again in the fall.  There are many, many unanswered questions about this amazing phenomenon.  The record flight for a Monarch in one day is 265 miles, an almost unbelievable fact.

When we were in Bangor, Maine, just three weeks ago, I had seen many migrating Monarchs and had photographed what was likely to be the last instar (larval stage) of the final generation there on milkweed, its favored host plant.  [Sorry about the photo quality]  Perhaps one of these individuals floating by me was the one I photographed.  The timing would be just about right.

Monarch Butterfly Caterpillar on its favorite plant, Milkweed.

Monarch Butterfly Caterpillar on its favorite plant, Milkweed.

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