SW Florida Nature in December 2023

With all the talk about global warming and sea level rise it was interesting to have a very high tide on the morning of Dec. 17, 2023. The photos of our backyard and dock underwater and a flooded street on the southern end of Manasota Key were not taken at the extreme upper limit, but they illustrate the shocking height of the tide that morning. Our house sits on a sand ridge about 9 feet above sea level and we thus do not worry about inundation anytime soon, but already the main road to the southern end of the island was blocked for hours. This of course presages future problems with accessing the island with a massive potential effect on real estate. The impact on nature has been less well considered but it is clear that only salt tolerant plants will survive in the tidal zone. Already we have lost many yard plants to salt water and are replanting to account for this. Unfortunately “halophytes” are a small subset of plants generally and offer few options for showy flowers and fruiting that will attract wildlife.

Although hurricane Ian (9/28/22) is now more than a year past, its impact is felt daily. We are still dealing with the massive effects of the winds on vegetation in our yard. The almost 30 year old live oak I planted had its top broken off which then blew onto my neighbor’s car port and our electrical wires. The resulting weakness in the remaining tree became more and more obvious and I feared that the rest of the tree would come crashing down and had it removed. One advantage of this was the removal of competition of the oak with an adjacent healthy white mulberry which is beloved of birds in springtime when it has fruit. A scary discovery was that cutting of the oak stump revealed a rotten spot in the center which would have surely destroyed the tree in time and caused it to fall. The amount of growth in this approximately 21 inch diameter stump far exceeded a slash pine of about the same diameter in Cedar Point which (see very narrow growth rings with age) was more than 90 years old. This is a great illustration of the restriction in growth of plants in native sandy soils due to extremely low nutrients, compared to a yard which had a septic tank for many years.

Another aspect of our early earth history which we do not think about much is the age of the sediments under our feet. The use of “gravel” in our area involves mining shallow shell deposits and spreading these on roads and trails. It is generally said that the Florida peninsula has alternately been under the sea and above it more than 30 times historically. But you may not realize how old some of these deposits are. I always take any opportunity to examine piles of shell “hash” to see what the age might be. So for example I found one pile at Myakka State Forest which contained an unusual extinct shell (see photo), a Wagner’s arc. This is a “guide fossil” indicating the middle Caloosahatchee Formation at about 3 million years old in the Pliocene Epoch! So when we become rightfully concerned about the impact of sea level change now, does it help to know that this has happened many times before?

This time of year there are not many native flowers blooming. I was fortunate to find a last remaining rose rush at Amberjack recently. This is in the aster family yet has an unusual flower- there are no disc flowers only ray flowers, as is the case for dandelions. The flower is attractive to a variety of pollinators; thus it does not specialize in attracting certain species of insect. This is the time of year that holly fruits are very obvious; this photo shows a female dahoon holly at Amberjack with its attractive fruits. Fruits of hollies are winter famine food so they remain on the tree until a hungry flock of robins passes by and eats them all.

Although you would think that Winter would not be a good time for butterflies, this is not always the case. I found the caterpillar of a Gulf fritillary on its favorite food, a poisonous corky stemmed passionvine. I regularly see cloudless and orange barred sulphurs on their favorite larval food of cassias. I saw this male black swallowtail (a mimic of the poisonous pipevine swallowtail) flying on a cool sunny day at Myakka State Forest. Monarchs are also regularly seen in our yard laying eggs on giant milkweeds. Since most of our caterpillars are eaten by wasps and other predators, I brought some very small caterpillars inside to rear them. They grow very rapidly into a large fat caterpillar which hangs up in the “J” position, sheds its skin and becomes a green chrysalis. Within a few days the chrysalis darkens and the orange wings of the butterfly developing inside can be seen. The chrysalis then splits open and a wrinkled monarch butterfly emerges and quickly unfolds its wings and flies away. This process is amazing and needs to be experienced firsthand.

I came across a yellow crowned night heron in the mangroves recently and admired its pattern- the male and female are identical. The very large strong dark bill is well suited for cracking crabs, the primary food of these beautiful birds. They are primarily a salt water species in our area but this is not always the case. On the other hand black crowned night herons are generally always found in fresh water. A single early loon that showed up beyond our dock is found in fresh water in summer and salt water in winter.

I have seen only one black iguana/Mexican ctenosaur in the past month. It was a juvenile on our back porch and still had some green coloring from its younger days. I theorize that the cooler nights we are having has been limiting the activity of all of the iguanas.

So although we are now in the early stages of winter, and some animals and plants are in stasis, there is still much to enjoy in the natural world. So do not hibernate- get out there and ENJOY !