Who Is Under Your Beach Towel

This blog has been hit many times by people looking for answers about the creatures they are sharing the beach with. I thought I should put together something more concise than my random posts to help out these curious folks, so here it is!     

Below you will find descriptions about common animals found on beaches near Charleston, SC.     

Birds

Probably the most ubiquitous and well-known animal at the beach is the seagull.  In South Carolina there are 5 species of gulls, with the Laughing and Herring Gulls as the most common during the summer months. They are opportunistic feeders and will scavenge anything they find on the beach, including dead fish and washed up jellyfish.  Some species have figured out how to open shells by dropping them on pavement or hard sand. The Laughing Gull, so named because of its comical call, has learned that a human with sandwich bags, coolers, or cracker boxes will probably drop crumbs, and therefore it is nearly impossible to eat on the beach without a squadron of screaming bird beaks announcing your culinary activities.      

Laughing Gull

Brown Pelicans

Another prominent bird is the Brown Pelican. Although you won’t often see it next to your beach towel, this bird is often seen diving into water head first for a fish, gliding just above the waves, or flying in formation.  With a wingspan of 7 feet and an odd-looking pouch under its bill, this bird is unmistakable though the smallest in the pelican family.  Every morning, these birds must stretch their pouches to keep the skin flexible and tear resistant.    

A tricky bird spotted flying around the beach looks similar to a seagull, but dives in the water pelican-style.  Terns are numerous along the coast and can range from mockingbird-sized to seagull-sized. They are mostly white with a black head and very long, skinny wings.     

Tern

Jellyfish

Though there are several dangerous jellies in the waters off South Carolina, the most common that washes up is the Cannonball Jelly. This harmless creature is planktonic, meaning it does not have much control over where it goes, but it does dive deeper during the night and come back to the surface during the day.  These jellyfish have a brown border on their bell and if you look closely, you can see the tiny ‘eye’ spots that detect light, direction, and scent molecules.  Their feeding organ is on the underside and they use it for catching plankton.  Many jellyfish serve as food for sea turtles.     

Cannonball Jellyfish

Crabs

There are many crabs that live at the beach, but the one most likely hiding under your beach towel is the terrestrial Ghost Crab.  These odd fellows spend their life running from the upper beach and sand dunes to the swash zone [where the sand is just wet] and back again. During the night they come out to feed on clams and spend the day in their burrows. Though they can breathe air, they must have wet gills to do so, that being the only reason they would enter the water.  Their holes are usually in dry sand, about an inch or so wide, and during the hotter days, are plugged up with loose sand.     

Ghost Crab

There are many types of swimming crabs that often wash up on the beach. Most common is the Speckled Crab though you can also find Blue Crabs occasionally. These crabs have modified, canoe paddle-looking back legs called swimmerets.   

Blue Crab

 

Ocellated Lady Crab Carapace

Last but not least of the true crabs, the Hermit Crabs often make appearances near beach towels.  Three species, the Long-wristed, Flat-clawed, and Striped, live in shallow water and are often seen scuttling back to the surf as the tide is receding. These little guys are foragers, picking food out of the sand, and they can often be observed fighting with nearby neighbors over shells.  They have a abdomens that look more like stingers than crab tails.   

Flat-clawed Hermit

Although not a true crab, the Horseshoe Crab needs mentioning.  Typically bottom dwellers, these harmless crab-like creatures come ashore to lay eggs. Occasionally their molts [shed exoskeletons] will wash up or be found floating on the surface of the water. The females are typically much larger than the males. Males have a front claw shaped like a boxing glove that helps them hold on to the shell of the female during mating.   

Horseshoe Crab

The Ghost Shrimp is an abundant, crab-like creature whose burrows are often the object of curiosity for many beachgoers. When the burrows are just near the swash zone, they will often bubble and spew while the Shrimp pumps water through its burrow system. The Shrimp make thousands of tiny holes in the sand, generally the only evidence that they are even there. They have one large, white claw used for defence and mantaining the burrow.  

Ghost Shrimp

 

Ghost Shrimp Burrow

Snails

There are many snails found on South Carolina beaches. Their shells are collected for their beauty, but little thought is put into what these snails do under the sand. 

Most of the snail shells you’ll find are from carnivorous creatures that attack and eat other mollusks. A great example is the Moon Snail or Shark’s Eye.  Moon Snails are responsible for the little beveled holes you see in other shells, the ones that look like they were put there to make jewelry. The snail creates these by licking the shells with its specially adapted tongue, called a radula. 

Moon Snail

Another predatory snail is the Knobbed Whelk, with its left-handed [opens on the left] counterpart, the Lightning Whelk. These snails pry open bivalves with the sharp edge of their shell.

Knobbed Whelk

Whelk and Ark

Alright, longest post ever.  I’ll start a Part Two as I think of more creatures.  Leave a comment if you’d like to see a specific one mentioned! Thanks!

Sepia Scenes: Salt Pruning and Shell-smashing Seagulls

Today’s post will be a potpourri of seaside related scenes with a tinge of sepia to give it that rustic look. :)

Salt Pruning

First off is the sodium-filled topic of salt pruning. 

Salt pruning occurs when ocean spray is blown onto the vegetation at the ocean side of the backbeach area.  The constant inundation of saline mist stungs the growth of the plants and makes them look like they’ve been pruned into wedge shapes, with the shorter side towards the ocean.  The photo above was taken from behind the wedges and the ocean isbehind the vegetation row. 

The above picture, and the one below, were taken at Fort Moultrie.

Shell-smashing Gulls

On to the gulls.  Although this behaviour is well-documented and nothing new to those who live on the coast, if you haven’t frequented beaches, you might find this behavior new and maybe a little surprising. 

Generally called shell cracking, many species of gulls engage in this behavoir, on both coasts and probably elsewhere around the world. 

The article, The Developement of Shell-cracking Behavior in Herring Gulls, [PDF] observes that first year gulls don’t have the hang of shell cracking and the technique, such as height the shell is dropped from and the surface on which it’s dropped are eventually learned and perfected so that the birds don’t have to make as many drops.

While watching the birds yesterday on the south end of Folly Beach, we saw some that just sat on the ground and dropped the shell from that height a couple times, and others that flew several dozens of feet into the air to drop their snacks.  The only problem with going so high and dropping seemed to be that other gulls had a better chance at getting a free meal.  Maybe that explains the reluctance at times to let the food fall? A couple of gulls were seen grabbing their food midair and re-releasing, sometimes repeating the process a couple times in one flight.  One herring gull, perhaps angry at a ‘flock-member’ dropped a shell right on the other gull’s back!

Trying to keep up with the falling morsel

Coming down to get the hard earned tidbit

Sometimes, it’s really hard to let your food get too far ahead of you

Falling with lunch

The gull’s food hit the water.  Wonder if that’s a harder surface than sand?

If you don’t stay with your food, it won’t stay with you

Thanks for visiting!