Spring in coastal South Carolina is a special time: while our friends to the north are zipped up against another month or more of cold weather, our thoughts return to boating, beach-going, and other outdoor recreation. Today, we’re asking folks who use SCDNR-managed beaches and islands like Capers Island to spend a few minutes on a survey to help shape the future of those properties.
Our nearness to wildlife-rich waters and beautiful beaches is a major contributor to quality of life and one of the primary reasons the region’s population is growing at record pace.
We’re not the only ones who depend on South Carolina beaches: dolphins strand feed along the banks, horseshoe crabs and sea turtles come ashore to lay their eggs, and dozens of shorebird and seabird species feed, rest, and nest there.
Unlike us, however, beach-nesting wildlife rely on access to quiet, safe shores for their very survival.
That survival has never been a sure thing for shorebirds, many of whom carve out their entire existence on the difficult margins where the sea batters the shore. These animals live by the tides, feeding on clams, worms, and crabs and laying their eggs in shallow divots on the bare sand. Predators, storms, and high tides are an ever-present threat to their nests and young.
Add to these natural challenges the increasing dangers of rising sea level and human disturbance, and you can begin to understand why shorebirds are in rapid decline across the globe.
Human disturbance is any event that interrupts an animal’s normal activities. It can therefore range from large-scale, societal patterns (such as habitat lost to support coastal development) to seemingly small, individual actions (such as walking by a flock of birds and causing them to fly).
The wildlife on our beaches are affected by disturbance across the spectrum, but biologists are increasingly concerned about the toll these latter, individual actions are taking on birds already under so many other pressures. Beachgoers and their dogs can add to these pressures by accidentally crushing nests, causing adults to abandon nests, preventing adults and chicks from accessing food, causing chased birds to lose critical energy, and generally reducing the amount of space available for birds to safely eat, rest, and nest.
THE SCIENCE IN SOUTH CAROLINA
Over recent decades, state biologists have learned that South Carolina’s coast plays an outsized role for the Atlantic’s shorebirds and seabirds. In spring, they’ve observed some of the country’s largest flocks of red knots on South Carolina beaches; in summer, around 40% of the Atlantic coast’s brown pelicans and 25% of the black skimmers nest on our islands; and in wintertime, up to half of the entire Atlantic population of American oystercatchers can be found here. The importance of a stretch coast centered on Cape Romain National Wildlife was recently honored with international recognition.
In these same places, SCDNR biologists have also observed human disturbance of birds for decades. They’ve taken steps to provide safe, protected spaces, such as seabird sanctuaries, where shorebirds can rest, feed, and nest. But a recent comprehensive study quantified just how widespread and persistent the problem of human disturbance is across the entire east coast.
Looking at dozens of beaches beaches ranging from Nova Scotia to Florida, a team led by biologists at Virginia Tech set out to measure the effects of human disturbance on five key species: American oystercatchers, piping plovers, red knots, semipalmated sandpipers, and Wilson’s plovers.
The teams recorded simple observations about the numbers of birds, humans, boats, vehicles, dogs, and predators present at each site approximately a dozen times across the year. They also looked at the behavior of the birds present – were they resting, probing the sand for food, flying, or on alert?
Patterns across the eastern seaboard were unmistakeable: “Shorebirds were rarely observed near an area if there were over 15 people within 200 meters,” or approximately two football field lengths.
Unfortunately, the study was also unequivocal about the fact that shorebirds view all dogs equally – as predators. Whether leashed or unleashed, the simple presence of dogs on the beach made birds more alert and less likely to rest.
But there were some bright spots, too – the study found that setting aside areas for nesting birds works. Birds were more likely (far more likely, in some cases) to occur in areas protected from human disturbance.
For people who are familiar with our coastal birds, these results may be unsurprising. When there are disturbances on every stretch of coast, flocks of birds cannot simply fly to the next beach. But what does constant disturbance actually mean for the birds? Does ‘being alert’ actually translate into negative consequences for birds? A lot of recent research has begun to tackle these questions.
In 2018, a team of researchers published the findings of several years’ worth of study of a federally threatened bird called the piping plover. From 2012-2016, they tracked the survival of piping plovers across the Southeast, including at five sites in South Carolina (Deveaux Bank; Kiawah, Seabrook, Hilton Head, and Harbor Islands).
The differences they found between popular beaches (lots of swimmers, sun-tanners, and beach-combers) and less-populous beaches (protected seabird sanctuaries or private-access islands) were clear. Not only did the birds on busy beaches weigh less – as frequent disturbance presumably made them less successful at feeding and fattening up – they were also less likely to survive from year to year.
For an endangered or threatened species that numbers in the hundreds of mating pairs, tiny changes in survival can have a powerful ripple effect.
WE WANT TO HEAR FROM YOU
There’s room for all of us on South Carolina’s beaches. Humans and wildlife can coexist in these special places, but it’s clear that shorebirds need safe, quiet places to survive.
We’d like to hear from you about how you use and enjoy our beach/island properties. SCDNR staff are evaluating how to best balance human recreation and wildlife needs on important coastal properties. If you visit SCDNR-managed beaches/islands such as Botany Bay, Capers Island, Otter Island, or Cedar Island, please take the below survey.
This survey should take approximately five minutes to complete and all answers are anonymous.
Disclaimer: The views and opinions expressed on South Carolina Wild are solely those of the authors, and do not reflect official policies, positions, or endorsements of activity or products by the South Carolina Department of Natural Resources.