Endangered Least Tern Colony Under Assault by Amphibious Vehicle

Endangered Least Tern Colony Under Assault by Amphibious Vehicle

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For the first time in years, on the north beach of Dewees, there is a least tern colony, which in itself is kind of big news! They have very specific habitat needs, and habitat loss is one of the key challenges for this bird. The smallest tern, Sterna antillarum, they nest in colonies in the edges of the dunes. There was a colony near Huyler House walk years ago, and our attempts to entice them back to nesting in the area were unsuccessful for years. Click here to read about our efforts in 2010.

Out on the north end of the island, there’s an incredibly quiet feeling, as dozens of terns wait patiently on the sand, their nests mere scrapes on the newly formed dunes. To the north, there are 60 miles of protected seashore, but the terns seem to require a specific zone of overwashed sand, nestled in the dunes. From a distance, you almost don’t notice they are there, so well camouflaged are they against the shell and landscape of our newly formed dunes. Their black caps and grey wings blend perfectly with the shell surroundings. Least terns are listed by the federal government as endangered, largely due to habitat loss.

 

 

Least terns nesting on the sand

I am often on that end of the beach for turtle patrol, and it’s really incredible how perfect the situation is for terns. The dunes are growing, with sea rocket and other sparse vegetation to provide small bits of shade. There are three huge tidepools where the large sandbar has attached, and they get flooded periodically by spring tides which bring new small fish to the pools. There are also much larger tidal inlets connected to the ocean which are teeming with small anchovies and silversides. Males fish and bring food back to mates on nests and chicks. Most of the time, the only sounds are the wind and the chattering of the terns.
Endangered Wilson’s Plovers seem to share the nesting area, and there was a single oystercatcher nest there for a while.

Wilson’s Plover

 

There were a few pairs of terns in the area last year, but last week I saw scores of birds sitting in the dune habitat, protecting nests. When disturbed, they fly at intruders, shrieking and defecating as a way to get you to leave. In the sort of heat we’ve been having, my very presence is dangerous, because if adults or chicks leave nests unattended to chase me off, eggs or chicks can perish in minutes in the hot sun.

When I realized that the colony had grown so large, Lori and I notified Felicia Sanders of SCDNR, and we agreed to get an official count, doing it very early in the morning so as not to disturb the birds unnecessarily. I took binoculars up there, as well as a camera and tripod, with clear plans to be finished by 7:30 am, so that the sun wouldn’t be as dangerous to the interrupted colony. I counted 49 nests with birds, and there were probably more. Adults flew over me, buzzing me and attempting to scare me away. It was a pretty magical morning– a few vestigial horseshoe crabs were near the edges, and I got a chance to watch the terns trying to chase off a ghost crab. A bird, nesting outside the posted signs, flushed and revealed two greenish speckled eggs. If I hadn’t seen her move, I would never have seen the incredibly camouflaged eggs.

The nest is a simple scrape in the sand.

Several terns raised wings to look larger and attempt to frighten off the intruder.
(Watch in HD for better results)
As the sun began to warm my back, I knew it was time to beat a hasty retreat, and scanned once more with binoculars to see the impossibly small outline of a chick in the sand. I was thunderstruck by the apparent fragility of the situation, and by the effective camouflage of the chick. An adult fluttered nearby, and I saw a second chick lie flat on the ground to “hide” in plain sight. Eventually they both raced after the adult, and I could only see them as slight shadows, a visual ripple against the backdrop of sand. I beat a hasty retreat. Two days later, in the same area, I saw an “older” chick who again vanished in plain sight.

adult approaches camouflaged chick

slightly older chick

Lori and I discussed moving the nesting signs, since obviously the birds weren’t reading them. We planned to have Nicole the intern go up yesterday and move the signs seaward to make the bird area bigger. After consultation with local bird experts, it was recommended that we temporarily close that small section of the beach during daylight hours so that well-intentioned walkers wouldn’t disturb the colony. This is the email that went to the community.
It’s ironic, then, that someone from a neighboring island with an amphibious vehicle came ashore for a little joy-riding. The ferry captain saw a group of people launching a new sort of vehicle from the IOP marina called a quadski. Billed as a high-speed amphibious vehicle, this jet-ski has wheels so it can come right ashore! Two vehicles were launched, and only one returned. And that’s because they came ashore right at the tern colony, using those large vehicles to spin and turn and eventually get caught in the tidepool that the terns were using for food. It’s a pretty large vehicle, and it was left on the island overnight.

amphibious vehicle assaults pristine beach
Approaching tern colony from the north before dawn. Vehicle visible from edge of nesting sign

This is a pretty large vehicle, and I am sure the rider was just looking for some harmless fun.  Motorized vehicles are not legal on the beaches of Sullivans and Isle of Palms, and I don’t think they should be here either.  My turtle probe is about 3 feet tall. It’s embedded in the sand about 6 inches, but that gives you a sense of the size of this.

Tracks went right up to the protected area:

And this is what I found where the eggs were the day before:

It is my fervent hope that the chick hatched and was able to get away.

To their credit, the owner of the vehicle returned yesterday morning before 7, and had the craft off the beach by 7:15, leaving only scars in the sand, several eggshells, and a few boards used for leverage. This morning, it was my sense that fewer birds flew over to see if I was invading their area, but that could be perception– I stayed pretty far away while I did turtle rounds. I am not sure how to keep the amphibious vehicle situation from happening again, but it’s something we should think about. From Dewees Island’s Osprey Walk to the north end of Cape Romain National Wildlife refuge, there are a lot of beautiful beaches that could be ruined by these things– sea turtle nests and other sand nesting birds are also in danger from unwary recreation seekers. Deveaux Bank, Crab Bank, and Bird Key are totally closed to recreation during nesting season except for designated areas. I wonder about the possibility of limiting access so motorized vehicles can’t do damage– I would much rather see kayakers and small sailboats land quietly in some of those lovely protected areas. I know the Dewees Island Environmental Resource Board and the Dewees Island Conservancy will be looking into ways to protect our fragile shore.

If you’re staying on the island, please limit your walks to early morning or evening when the sun rays aren’t as strong.