Nature’s Fall Delights in SW Florida

November 12, 2017

Nature Notes by Bill Dunson

As approaching winter is beginning to extend its icy grip across the northern states, on the Gulf coast shoreline of Charlotte County in Florida we still experience some very warm days interspersed with the occasional passage of a cool front.

We are fortunate to live along the gulf coast shoreline and can switch from observations of marine and terrestrial life sometimes by just turning our heads. I recently noticed an unusual Caribbean crab has continued its colonization of this area- the distinctive mangrove root crab (Goniopsis) is a tropical species that I have seen in two areas in creeks that are tributary to Lemon Bay. Why are they here- is it just a temporary extension of their range or has gradual global warming contributed to their spread? Only time will tell, but in the similar case of the tropical upside-down jellyfish (Cassiopeia), it occasionally appears here in considerable numbers during the summer and then disappears during winter.

The mangrove skipper is a spectacularly-colored butterfly whose caterpillars feed on red mangroves. Their iridescent blue color is likely due to refraction rather than a pigment- note that the left forewing is brownish when viewed from a different angle.

On Englewood beach my wife Margaret noticed a flock of common terns, which are migrating from their breeding areas in Canada and the northern US to the coasts of S America. The dark carpal bar on the wing is distinctive but they resemble a number of middle-sized terns. So when you go to the beach this time of year it pays to carefully examine the flocks of seabirds that rest there.

While I was south of Stump Pass recently I was astonished to see that the “Spit,” that was originally truncated from the southern end of Manasota Key during former dredging of the pass, has now virtually disappeared and is now present only as a sand bar. On this bar there were two eagles that were acting friendly and them suddenly began to mate. Considering the busy surroundings it is interesting that these love birds were not more shy. They are likely the pair that nests at Cedar Pt and thus are “urban eagles” acclimated to human activities.

On land I also observed some interesting animals that I do not often see along the coast. There was a band winged dragonlet in Amberjack Preserve in the “obelisk” position which is believed to minimize heat gain from the sun. The darker colors of the abdomen and wing patches suggest this is an andromorph female, one which resembles a male. This peculiar type of coloration is not uncommon in some odonates and is suggested to be an evolutionary strategy by the females to avoid unwanted sexual attention by the males. Nearby in Amberjack we observed a white winged dove which is a fairly rare sighting in our area, although it used to be more common. The reason for this is unclear although this primarily SW US/Mexican species might be negatively influenced by competition from the much more common Eurasian collared dove.

In our yard on Manasota Key I was pleased to see an adult Florida box turtle foraging in the grass. Our application of leaf mulch along the edges of our lot, planting of shrubs and other cover, and exclusion of dogs has apparently provided year-round habitat for these beautiful and very long-lived reptiles. We have also planted many species to attract birds, and provided water drips/baths and a migrating/wintering orange-crowned warbler was recently seen twice in our yard. This relatively inconspicuous warbler breeds in the western US and Canada and migrates to the N American coasts and Mexico in winter.

So in mid-to late November it is time for the naturalist to remain very alert for migrating birds that are not often seen and are sometimes hard to distinguish from more common species. It is a good test of our powers of observation to detect these birds and keep track of all seasonal natural events.

Bill Dunson

About Bill Dunson

Bill Dunson, born in rural Georgia, skipped 12th grade and went directly to Yale. Bill subsequent-ly received a PhD in Zoology from the University of Michigan, studying softshell turtles. Bill is Professor Emeritus of Pennsylvania State University thanks to a career spent entirely at that institution, teaching and doing research on the physio-logical ecology and ecotoxiciology of reptiles, amphibians and fish. Always curious about nature, Bill has dedicated his life to learning and sharing his knowledge with others. He has served on many advisory boards here in Southwest Florida to preserve the water that gives life to our region.

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