Monarchs in the Maine islands

The islands are known for their dark covering of evergreens and moss, but in the occasional patches of open grow blueberries and blackberries, cranberries.... and sometimes milkweed. And the favorite food of monarch butterfly larvae is milkweed leaves. Unlike the milkweed in MA or MI, where I might search ten minutes without finding a larva, the patches I've found on Monhegan Island and another

teem with the little critters,

often stripping stems bare of any leaves to the point the larvae must set out on a dangerous journey to find another plant, one that still has leaves.

We also wondered at the small larvae present at such a late date: surely frost will come soon and kill the remaining larvae.... why would the adult keep producing eggs rather than heading south? We even saw one mating, an obvious waste of energy.

Further thought made this behavior far more reasonable. I think this tattered adult, still mating and (probably) laying eggs gave a clue: it has zero chance of struggling very far south, of beating old age and the advancing frost of fall.

On the other hand, the frost might come late enough for it's offspring, vibrant and young and strong, to wing their way south and pass on genes.

So... the opportunity cost of laying eggs is zero as there is nothing else it could do to pass on it's genes.

Yes, I know some folks might simply enjoy the beauty of nature, but I like to look and wonder and understand.

Then again, there IS the simple beauty to appreciate...