Fall Natural Delights

December 13, 2016

Nature Notes by Bill Dunson

 

 

 

One of the true delights of spending the fall in SW Florida is that you can continue to enjoy seeing a wide variety of plants and creatures actively pursuing their lives. There is of course a considerable seasonal change in flowering, growth and species which are present, but the naturalist can continue to find great pleasure in the very rewarding hunt for new sights and sounds in the natural world.

A new observation for me in Charlotte Co. was seeing Indian pipes at Prairie Creek Preserve near Punta Gorda. This unusual flowering plant lacks chlorophyll so must derive its nutrients from another source, in this case from mycorrihizal fungi that live in a symbiotic relationship with tree roots, The habitat was a scrub community with white sands that is quite low in nutrients; this life style represents an unusual variation on a parasitic mode of life.

A very common exotic plant that is widely found in our area is the balsam pear , a stinky vine with yellow flowers that are attractive to butterflies. The fruit capsule is orange and opens to reveal seeds which are covered with a bright red and delicious aril, which is edible. The seeds are toxic. This illustrates very well how some plants are designed to disperse their seeds by advertising them to birds in this case, and providing a reward for eating them, but protect the seeds themselves with toxins. It also provides an object lesson about eating wild plants- do NOT eat any seeds unless you know they are edible!

Another interesting lesson in evolution was provided by finding both the common buckeye and the habitat specific mangrove buckeye butterflies. They are quite similar and differ mainly in the relative sizes of the two eye spots in the hind wing and the white/tan margin around the large eye spot in the fore wing. Likely the mangrove is a specialized offshoot from the widespread common buckeye and is restricted to mangrove areas where the caterpillar feeds on black mangrove leaves. The position of the eye spots around the margins of the wings seems well designed to divert the attacks of bird predators away from the cryptic head and body.

A snake that I see very rarely is the rough or keeled scale green snake which I found sunning on a road in Prairie Creek Preserve. It is an amazingly camouflaged snake that feeds mainly on insects. The more northerly species is the smooth scaled green snake. The significance of the difference in scale morphology between the two snakes is unclear. The camouflage is most likely directed against detection by bird predators since mammals generally are color blind and the insect prey seem unlikely to respond to predator color in contrast to movement.

Another reptile that is rarely seen is the small-sized gopher tortoise . The adults can be common so there must be considerable predation on the younger and more vulnerable stages that forces them to be well hidden. So when I found a hand-sized gopher in a neighbor’s yard I was surprised and interested to see how old it might be. When I examined a scute on the carapace, I counted about a dozen rings; this estimate of age can be equivocal but it indicates that this tortoise is about 10+ years old. This illustrates how slowly gophers grow and how different they are from many other vertebrates we encounter. The width of the rings also varied, indicating that growth was much better in some years than others. But the fast growth years were scattered and not concentrated in the youngest times as occurs generally in trees. This tortoise was moved from the roadway by a passing truck driver in an interesting demonstration of compassion for these vulnerable chelonians that represent an early stage of reptilian evolution.

Another vulnerable and disappearing species is the loggerhead shrike , which is still common in winter along the four mile entry road into Prairie Creek Preserve along a farm/pasture. It is a small but fierce predator on small animals which it sometimes impales in plant spines or barbed wire fences. Note the hooked bill and that the dark eye is camouflaged with a black stripe.

I recently observed an old acquaintance along the beach at the southern side of Stump Pass. This adult male snowy plover was banded 7.31.14 at St Joseph State Park in the FL Panhandle. I observed it several times last winter also in this same area and others have also seen it. This is a remarkable demonstration of the site fidelity of birds which migrate to the exact same area year after year. This plover has done well to have survived for at least three years and likely has bred at least three times. I wish it well and hope that it escapes the many dangers of the open beach, including the upcoming dredging of Stump Pass and beach re-nourishment.

Bill Dunson
Englewood, FL

Nature Notes by Bill Dunson

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.

View all posts by Bill Dunson