Darwinian Defect

Vero Beach (wikimap)
27 39.646N 080 22.224

We love herons; especially the Great Blue Heron. We used to have a heron that visited the pond at our house, just outside the kitchen window.

As we cruise the US East Coast, we encounter lots of herons. I've learned to recognize the angry kraaaaaak noise that they make when they are angry or disturbed. One thing about their behavior though, leads me to fear for their survival.

When one sails or motors in a boat along a river, creek, or canal, one frequently comes upon a heron standing on the shore. Herons are shy and don't like you to come close, so they fly away. The problem is that the herons fly several hundred meters away in the direction away from the boat, then land on the shore. Of course, that means that the boat will catch up to this new position in a few seconds. The heron flies away again, and again and again until finally it decides to fly in a different direction or it resolves itself to stand still and let the boat pass.


I think this is a Darwinian defect. The heron's behavior magnifies its stress many times over. Seemingly, all the other birds and animals have better evasion strategies than does the heron. Let's hope that herons survive long enough to evolve a better strategy.