My resolution for the new year is to ramble more and sit less. So to satisfy this goal I spent a great deal of time exploring the beaches and bays of Palm/Knight & Don Pedro Islands, FL, and the nearby Wildflower Preserve. I have found that I am never bored on such excursions and always find something of interest.
The “beautiful swimmer” the blue crab is a characteristic estuarine predator of wide distribution but only along a narrow coastal zone. The larger males with blue claws contrast with this female with bright red tips to her claws. This exerts a powerful attraction on the male rather like human “lipstick.” Another creature nearby in some shallow coastal bays is the cryptic ragged sea hare, a shell-less snail that may react to a threat by releasing a dark blue dye. My grandson finds it amusing to squeeze them to elicit this reaction. A distantly related mollusc was the source of royal purple used to dye the robes of emperors. This “ink” is of course used as a defense and might be toxic.
The fresh water ponds at Wildflower Preserve have an abundance of large hard-shelled freshwater turtles, primarily the peninsula cooter. Their enormous egg-shaped shells reflect the evolutionary arms race with alligators in which they try to avoid being crushed for dinner. This time of year the females are laying eggs, many of which are excavated and eaten by the exotic armadillo. If you get a chance, look at the top of the turtle’s head and see if there are two hairpin-shaped loops which are distinctive in this species. The females are much larger than the males, the better to produce more eggs. In some species where male combat is part of their behavior, males can be larger than females (snapping turtles).
One of the best bird shows is found on and near the beach. I have found the time just before and after sunset can be excellent for observing this spectacle. We often have large flocks of black skimmers resting on the beach and flying up into the setting sun. It is comforting to see so many despite the numerous dangers they face. One way the local ospreys protect their nest is to build it on the top of Norfolk Island pines. This reveals a major advantage of planting and retaining such exotic trees since otherwise there are very few elevated nesting platforms for these remarkable raptors in the human-dominated landscape.
Mixed in among a large flock of terns, skimmers and gulls I noticed a few large terns that were different. The photo shown here illustrates the differences between the larger Caspian tern on the left and the royal tern on the right. We see Caspian terns rarely on the beach since they are primarily a bird of inland freshwater habitats except during migration. This illustrates a common dichotomy among birds- a division by habitat salinity. Another example would be the yellow crowned night heron which is mainly found in saline habitats whereas the black-crowned night heron is mainly a fresh water inhabitant.
The most exciting bird on the beach mixed in among a large flock of red knots was this individual with a band on its leg. The code (7CT) is quite clear and I was able to find out that this bird was banded Sept. 2, 2009, at Monomoy National Wildlife Refuge in Massachusetts during migration. Although we are generally familiar with long-distance bird migration, the incredible nature of it becomes more real when you have an individual before you which winters on the west coast of FL, and flies north along the east coast of N. America to its breeding ground in the Arctic. For such a tiny animal this is an amazing feat and should inspire us to be sure that their places of breeding and migration are protected. This is one of the shorebirds that depends heavily on the abundance of horseshoe crab eggs in the Delaware Bay for renewal of their energy stores during migration.
So join me and get out there, ramble, and enjoy the natural world that is such a source of wonder and beauty.
Bill Dunson, Englewood, FL & Galax, VA