Predators Large and Small at Wildflower

January 21, 2011

Nature Notes by Bill Dunson

 

Sometimes while leading nature walks I encounter the idea that if one has walked an area once, there is little reason to return. Nothing could be further from the truth since repeated walks at the same location continue to reveal a myriad of natural wonders that one would miss without these frequent opportunities to encounter critters on the prowl. My walk at Wildflower Preserve in Charlotte County, FL, yesterday illustrates this very well when I ran into a bobcat twice as well as two tiny spider predators on a micro-scale.

This large bobcat was almost leisurely in its slow withdrawal from human intrusion into its space (see photo of north end of south-bound bobcat). It was a large cat and rather dark in color. In one instance it seemed to be investigating some otter f eces and in another finishing a meal of a grackle. This is my first sighting of a bobcat on this property despite many hours spent there. The cat walked away slowly on one of our new trails and I almost wonder if it has recently appeared here and found the trail system to its liking? It is exciting to know that a large predator is in our midst in this suburban park and there is always a chance of encountering it.

At an entirely different scale I noticed a dark blob in the midst of some leaves on a small twig and had a closer look. It turned out to be the second “nest” I have found of a female green lynx spider and her ball of baby spiderlings (see photo). While she is normally a predator that stalks and pounces on her prey without a web. she has here spun a web to protect her young and remains nearby in a protective mode. Indeed when I poked a finger into her sphere to move a leaf, she bounded forward to repel this intruder; such protective mothers are said to spit venom as a defense ! The degree of her maternal interest is shown by the shrunken appearance of her abdomen, indicating that she has been fasting while tending to her brood. Such maternal instincts in a lowly spider are remarkable since we humans often equate such behavior to higher level altruistic feelings. Yet this could easily be attributed to the “selfish gene” concept whereby it is in the most basic interest of all creatures to propagate their own genetic heritage, and is thus in fact the most selfish act of an individual.

A close encounter with another local and very interesting spider came when I almost walked into a web of the orchard orb-weaver. This tiny spider attracted my attention since it has some large orange spots on the rear abdomen (see photo) and also in some cases underneath as well (see photo sent to me by Dennis Paulson). Now whenever an animal advertises its presence with bright colors you may suspect that it is poisonous or toxic, or pretending to be so. Indeed Dennis suggests that it resembles a black widow and this could be a type of mimicry. Yet from some angles this tiny spider is rather inconspicuous and when it hides in a nearby leaf or drops to the ground, may be impossible to find. The potential predators with color vision are mainly limited to birds and it would be quite interesting to evaluate their response to this spider.

So I find that repeated visits to a favorite natural area are not only fun but provide a sort of “timed release” of nuggets of natural history to educate and inspire.

Bill Dunson, Englewood, FL & Galax, VA
wdunson@comcast.net

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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