Predators at the Beach – Large and Small

January 26, 2014

Nature Notes by Bill Dunson

Much of human life in Florida revolves around beach activities and we tend to forget that it is a habitat for many animals. We think of the beach as a happy place to relax and enjoy the sun and surf. Since for animals the beach is a place to live, breed, hunt and feed, they must have a very different perspective. As animal habitat, the beach is a difficult place because it lacks cover, and is constantly changing in form, temperature, and in the relative amounts of water and land. For this reason you tend to find specialists at the beach which may be found elsewhere only rarely. For example one of the favorite foods of shorebirds is the mole crab, a crustacean that burrows within the surface sand of the lower intertidal zone and filters plankton and detritus for food with its antennae. This creature can live no where else than on the lower beach. These are a preferred food of fish that are feeding in the water just below the intertidal beach and are often collected by fishermen for bait.

Starting with the largest predators, there are sharks of scary proportions feeding just off the beach. The photo shows a large sandbar shark (in the same family as the great white) recently caught by my son at Stump Pass on cut fish bait. Such impressive predators almost never bother humans; however it is probably wise not to swim after sundown! They are a major predator on fish.

Birds are common intermediate-sized predators that both feed and rest on the beach. The willet shown here feeds often on mole crabs as do numerous other shorebirds such as red knots and sanderlings.

A smaller nocturnal predator and scavenger that is very common on the beach at night is the ghost crab. It lives in holes during the day and emerges at night to search for food. Although it may feed mostly on beach-washed carcasses, it can also be highly predatory and for example feed on hatchling sea turtles.

Some of the most ferocious predators are tiny, such as the tiger beetle, shown here mating on the beach. They have massive jaws for their size and are like a tiny tiger among the small denizens of the beach. Their larvae also are predatory although they live in holes in the sand.

So when you next go to the beach, look around and observe some of the dramas of life and death that are unfolding around you. Our beach playground is wild animal habitat which contains some of the most predatory creatures in nature.

Bill Dunson

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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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