Nature is HOT in Florida Fall

November 10, 2015

Nature Notes by Bill Dunson

Although I am generally anxious to leave our VA farm soon after the first frost, this year it has been unexpectedly warm in FL even into November. This is a shock to humans unused to such hot and muggy weather, but it yields a bonus in that critters tend to be more active and plants flourish.

This green lynx spider is guarding her eggs. She does this apparently without eating and her shrunken abdomen illustrates her devotion to her progeny. Such maternal behavior in higher life forms is considered commendable and even altruistic, but this illustrates how even primitive species are equally devoted to protection of their babies due to the evolutionary imperative to procreate their genes.

I was happy to get this photo of a great pondhawk dragonfly, which I do not see very often; it is limited to S FL in the eastern US. It has a huge thorax and a slender abdomen and is a rapacious predator on insects. It is somewhat unusual in that the coloration of both sexes are similar and they strongly resemble the female (but not the bluish male) smaller eastern pondhawk. There is so much we do not understand about the significance of such variation in color and pattern.

A very confusing group of butterflies is the hairstreaks. On a hike in Charlotte Flatwoods Preserve we came across a number of the mallow scrub hairstreak which is restricted to S FL. Not only are there other types of similar hairstreaks, but they also resemble the blues, both of which are tiny and require some study to identify. Aside from the challenge of identification, I find these butterflies fascinating because of their unusual color and pattern. The eye spot on the outer hindwing and the short “tails” appear to be an head mimic that is designed by evolution to divert the attack of close-up predators such as jumping spiders away from the vulnerable head and body. At a distance this butterfly is well camouflaged.

A butterfly that is certainly conspicuous is this clouded sulphur which is bright yellow, shown here drinking nectar on some red salvia flowers. But its seems to limit predation by flying not only fast, but in an erratic pattern with short stops at flowers.

The opposite extreme in animal locomotion is this FL box turtle which can only defend itself by closing up inside its shell when attacked. The patterns on both the upper (carapace) and lower (plastron) shell are quite striking and illustrate how artistic natural coloration can be. It might be that such beautiful patterns of the upper shell are actually a type of camouflage since they may disguise the shell by breaking up its outline in the dappled shade and sun of the forest floor.

On a visit to Red Bug Preserve in Sarasota I found this coot feeding among the blooming floating hearts. Not only was this a charming scene, it illustrates how coots and moorhens feed by picking up plant and animal material from the shallow surface waters. The apparent decline of such birds that feed on shallow vegetation in lakes appears to be due to competition with the introduced African tilapia fish which is very common now in fresh water lakes.

Wading birds are attracted to natural features of our yard which lies along the shores of Lemon Bay. Thus in this photo you can see a little blue heron on the dock, and a single snowy egret and a group of white ibis feeding along the waters edge. Such a mixed species flock seems to be of mutual benefit if contrasting feeding styles yield prey that may be less available when the species feed alone.

Perching birds or passerines are primarily attracted in our barrier island yard to fresh water supplied by a drip; this yellow throated warbler likes to drink directly from the drip and then go down to the bowl and bathe.

Soon enough we will be shivering from the periodic NE winds of cold fronts, but for now we enjoy the sultry southern breezes and the active behavior of animals uninhibited by cooler weather.

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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