Small Fierce Predators Stalk Greenway Park

 

 

Hundreds of people use the beautiful Boone, NC, Greenway Park daily for recreation and likely do not think about the myriads of small predatory interactions that occur there among the resident animals. Indeed if you were the size of their prey you would definitely not want to be anywhere near these creatures.

Insects are among the fiercest of predators although some are quite beautiful also. The ebony jewelwing damselfly male is a stunning iridescent greenish/blue which presumably serves to attract a dull-colored female for mating. This type of mating system normally indicates that the female is choosing the males that are the brightest and presumably the most fit in terms of their genes. Their predatory nymphs are aquatic and the adults are usually found near water We called them “snake doctors” when I was growing up in Georgia since they would sometimes land on water snakes while they were basking on branches.

A somewhat similarly colored greenish iridescent terrestrial predator is the six spotted tiger beetle, yet males and females are colored the same. The purpose of the bright color is not known. They have large jaws and eyes and hunt actively on the ground for small insects, but also can fly. The juveniles live in burrows in the ground and catch prey at the surface.

One of the most obvious predators living in marshes and ponds is the bullfrog, which advertises its presence by a loud call. This is a male as shown by the large ear drum which is wider than the eye. Males defend their pond territories by calls and fighting, and the size of a male and his depth of call can intimidate rivals and attract females. Bullfrogs are so-called “gape-limited” predators since they will eat almost anything that they can swallow, not only small prey such as spiders and grasshoppers but also baby alligators and snakes.

Snakes can of course return the favor and eat small frogs and tadpoles, as well as a wide variety of small prey. The amphibious garter snake is well known to most people and they do not usually fear it. But surprisingly, garter snakes actually have a mild venom, as do ring-necked snakes, that assists them in subduing prey. The occurrence of stripes on garter snakes is an interesting pattern that appears to make it harder for their predators such as birds to focus on a spot to attack them as they slide through the grass.

The northern water snake is common but often mistaken for the poisonous water moccasin which does not occur in the Blue Ridge Mountains where Boone is located. This individual was seen basking along the south fork of the New River on a cool day, in order to raise its body temperature to digest prey more efficiently. It specializes in feeding on aquatic prey and gives birth to live young in contrast to the predominant terrestrial ophidian predator, the black rat snake, which lays eggs. Few venomous snakes pose any threat to humans, yet there is a wide spread fear of all of them which has little factual basis. Indeed it appears that the phobia some people have for snakes is a learned cultural feature and not innate.

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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