A Florida Thanksgiving Nature Ramble

November 28, 2014

Nature Notes by Bill Dunson

While many people celebrate Thanksgiving with football, shopping, and food, I continue to find my greatest pleasures in the natural wonders which surround us every day. Indeed some of the most overlooked aspects of nature can be the most intriguing. For example while walking at Stump Pass Beach State Park I noticed that a bay bean vine had a few flowers on it. On closer inspection this flower is seen to be of great beauty and is the precursor to a familiar bean pod. The beans can be toxic due to the amino acid canavanine which substitutes for arginine in protein synthesis and disrupts metabolism.

This time of year the Christmas berries are striking but will not last long since the birds eat them quickly. Since this is a member of the often poisonous nightshade family, it might be wise to avoid eating them although the famous Chinese “goji” berries are widely eaten and are in the same genus, Lycium.

We have planted the Mexican sunflower in our yard and the flowers are very attractive to bumblebees and sweat bees. The sunflower is a classic aster or composite flower made up of many individual disc and ray flowers. This bumblebee has a fuzzy thorax to maintain a warmer body temperature to allow foraging during cooler parts of the day. I found from personal experience that they will fiercely protect their hive and attack anyone who disturbs it.

One cool morning I noticed this zebra butterfly in a resting pose on a sea grape. It is not common to find butterflies while they are “sleeping,” likely because they hide themselves from predators. Of course the slow flying zebra is protected by toxic chemicals retained by the caterpillar which feeds on passionvines. But note also that the outer wing surfaces are camouflaged, unlike the brighter inner surfaces which may be a warning to potential predators.

We live on Lemon Bay and I spend a lot of time along the water, yet have not seen the “upside down jellyfish” Cassiopeia for several years. They are a tropical species that occasionally comes this far north and are a distinctive presence lying on their backs on the bottom and pulsating. They are unusual in that they contain symbiotic algae in their tissues which photosynthesize and share carbon compounds with their host. Yet to my surprise in one particular local marina I found a number of jellyfish on the bottom. Some were unusually large for this northerly location and it is a mystery to me how they happen to be here. Could they have come in originally in ballast water from one of the boats or have they simply survived longer here due to warmer waters?

An unusual avian visitor to this area, the whimbrel, illustrates one of the more bizarre bills designed for probing in sandy and muddy substrates. This long curved shape is shared with curlews and ibises. Some smaller dunlins sitting nearby have only a slight downward slant to their bills and they use them to probe in the mud. A very common winter resident on land, the yellow rumped warbler illustrates a very different bill shape designed for picking up small insects and fruits such as wax myrtle. These wide varieties in bill shapes are a wonderful example of evolution for specialized means of food gathering. However it is interesting that white ibis are now using their down-curved bill designed for aquatic probing in capturing small prey in lawns.

One of the most beautiful aspects of nature is simply the views in various habitats. Among the most spectacular are sunrises and sunsets and I show a sunset I captured on Thanksgiving eve over Lemon Bay behind our house.

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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