On Friday afternoon I spent some time observing the coquina clams’ behavior during receding tide. What I didn’t see was a lot of coquinas digging themselves out on the high beach, so that part of my idea was bad. I did seem to see a lot of coquinas rolling down the beach and then digging in once they moved down a bit. Maybe a positive reinforcement bias, I don’t know. So I think it’s still possible that the coquinas know the difference between an incoming tide and a receding one, and change their behavior accordingly.
However, I also found that at least a few coquinas do get left behind by a receding tide, and seem to do just fine buried in the drying sand, so maybe it’s not such a big deal that they get pulled back in by a receding tide. Maybe they prefer to be in the swash zone, but are content if they are left higher on the beach, and resume their behavior once the tide returns.
At any rate, it was fun to think about them and how they deal with the problem of changing tides. I’ll keep reading to see what’s already known about their behavior.
On Saturday morning I made a very short beach walk, because we all had to pack up and head for the airport. One final picture of “my nest” with the Gulf in the background.
In 35-45 days, if all goes well, from that spot will pop around 100 tiny loggerhead hatchlings. They’ll scramble for the gulf and disappear for 20 years or more. If one is very, very lucky, she may return to this very beach in 2033 or so to build her very own nest in this same spot. I hope she makes it. Good luck, baby turtles, and goodbye for now to the gulf and the beach. We’ll miss you!