|Great white heron|
Thursday, January 29, 2015
Natural Wonders of January in SW Florida
We have had at least one light frost within five miles of our house in December and a series of cold fronts in January on an almost weekly basis. But temperatures soar into the high 70's and even 80's in between these cooler periods. Flowering of native plants is at a low ebb at this time and insect life does diminish. But there are many aspects of natural history that continue to provide fascination for the naturalist.
For example I came across one example of a wonderful flower, the seaside gentian which I have never seen before. It is unusual in that it grows close behind the beach dunes and does not seem to be obviously adapted for this periodically salty and dry habitat. It was also blooming far earlier than normal since it is typically a summer bloomer, when the rains are much more abundant. One of those many mysteries of nature I guess.
Another fortuitous discovery was a female polyphemus silkmoth fluttering at the base of an oak tree. This is one of the largest of our moths and one of the most striking. When undisturbed it is well camouflaged but if prodded it opens its hind wings to reveal the most amazing eye spots. Clearly this behavior and coloration are designed to strike fear or at least caution into potentially predatory birds.
The large eye spots must mimic an owl's face or perhaps snake eyes and their fine structure is quite detailed indicating that evolutionary selection has refined the basic eye spot into a more specific eye mimic.
On cool and sunny days reptiles are often seen basking and a presumed female alligator was found with a number of babies clustered on her head and back.
Gators are known to be quite maternal and these young ones must represent last year's brood which she is still protecting. Her blood may be "cold" but her heart is warm! Since crocodilians are the surviving archosaurs or ruling reptiles this indicates that the dinosaurs may have had complex behavioral patterns also. Since baby gators are just a snack for many predators the continued protection of the mother may be very important for their survival.
Bald eagles are raising their young now and this photo was taken Jan. 16 at a nest along the Pioneer Bike Trail just south of the East Branch of Coral Creek. Unlike most birds they are winter breeders which may be related to their food supply and the long period of development necessary for these young raptors.
For such a strong predator it is touching to see how carefully the adult pulls off small pieces of food and hands them to her babies (two in this case). Young eagles go through about four years of maturation and changes in plumage before becoming the iconic adults we are so familiar with.
An unusual sighting at Myakka State Park was a great white heron, a southern morph of the great blue. I show photos of the great white for comparison with a great blue on my dock. The great white has yellow legs and shorter head plumes in addition to being white. The great egret is much smaller with dark legs. The occurrence of dark and white morphs in wading birds is common and it seems that such variation must be related to differences in feeding efficiency for different prey and possibly different feeding behaviors.
Standing close to the great white at the park was a wood stork which has a very different feeding behavior- it wades in shallow water with its bill open and shuffles its bright pink feet to scare up prey. Creatures that touch its bill are caught by an extremely rapid snap of the bill cued only by touch. The smaller snowy egret uses a similar "snowy shuffle" of its bright yellow feet to scare up prey which are speared by a visually directed jab of the beak. All of these variations in morphology and behavior seem designed for avoidance of competition among the various species of wading birds.
So wherever winter finds you, go out and enjoy the glories and mysteries of nature.
Englewood, FL and Galax, VA