Crowds, condos and trash take their toll on beach nesting shorebirds
Updated: Nov 2, 2022
By Staci-lee Sherwood
Since the 1970s it’s estimated that shorebird populations have plummeted a whopping 70% in North America with some species hit harder. Adding to polluted water, loss of habitat and natural predation we have newer problems especially here in Florida. The problems facing shorebirds are global though some issues are more prevalent in certain areas. The one constant is that human encroachment is on the rise as shorebird populations are on the decline.
As one of the big boating capitals shorebirds must contend with boats not only near the shoreline but often anchored right on the shoals. Dog parks have become popular and with that loose dogs often run through nesting colonies. Every summer we have fireworks on the beach and now noisy powered hang gliders. Plastic pollution, beach trash and coastal development have all but obliterated their once pristine habitat.
American Oystercatchers have an equally perilous future. Their striking colors make them much sought after by photographers. Their diet mostly consists of shellfish like oysters and crabs. Oysters are known for their ability to clean the water of pollutants. A healthy oyster bed means a balanced ecosystem which is paramount to providing food for shorebirds. For the two pairs I watched in 2020 their mortality rate was higher than normal. The Lake Worth Lagoon has a long history of pollution. Years ago the oyster bed was replaced but the lagoon has yet to bounce back. After decades of dumping the water is not clean enough to provide much food for seabirds. A lake this size should have a lot more birds hunting for food and nesting. At the height of nesting season only a few pairs can be found and mortality runs pretty high way over 50%.
This species can be found nesting on the beaches along the coast as far north as Massachusettes down to Florida though never further south than Palm Beach County, Florida. A favorite spot for a couple of AMOY’s is Snook Island Natural Area. Mortality rate for these two pairs runs about 50% but for the rest of the state the population is quickly decreasing. Oysters are most affected by a warming ocean.
A concern of thinning shells due to ocean acidification has been studied and the future does not look bright. For the oystercatcher that can spell extinction since that is their food source. With food scarcity on the horizon the remaining sustainable oyster beds will be a priority for human harvesting which could leave the oystercatcher with no food. American oystercatchers are protected by the U.S. Migratory Bird Treaty Act and a State-designated Threatened by Florida’s Endangered and Threatened Species Rule.
An adult American Oystercatcher hunts for oysters among the rocks in Lake Worth Lagoon in south Florida.
American Oystercatcher chicks blend in with the natural surroundings and don’t get the striking colors of the parents until it’s time for them to fledge.
Airboats have become a newer disturbance that can often flush whole colonies.
Photo : Patrick Leary
Black Skimmers get their name from their ability to skim the top of the water for fish in what looks like a delicate ballet. Their striking colors of red, black and white make them a favorite among birdwatchers and photographers alike. Known to nest in large colonies on the gulf side of florida but on the east coast we get a few colonies. One such colony chose a group of manmade islands. These islands are tiny strips of sand and rock situated in the middle of the intercoastal. Surrounded by boaters the waterway can be very busy for the Black Skimmers and this often interferes with foraging for food. The colonies are safe from harassing dogs and beachgoers but do have to contend with drones and polluted water.
Black Skimmers nest in colonies which offer protection from intruders. Some of these colonies number in the hundreds. While safety in numbers can apply to natural predators, like hawks and gulls flying overhead looking for a quick meal, they can also make them as easy target for other predators. Anyone wanting to do harm can injure an entire colony if they were to throw firecrackers at them. Even unintentional harm can cause a colony to abandon their young if they feel threatened by dogs running loose on the beach every day. Both of these have happened in the past. The black skimmer is protected by the U.S. Migratory Bird Treaty Act. It is also protected as a State Threatened by Florida’s Endangered and Threatened Species Rule. This species is particularly vulnerable to human disturbance and colony collapse can easily happen. Management by volunteers who often guard the nesting area, place signs warning people to stay and educate beachgoers are often used to protect the colony.
A Black Skimmer skimming the water for food
This photo was taken at St. Pete beach in Florida in 2019 by Karen Mason.
For those who help monitor nesting shorebirds the above picture is all too familiar. Despite their being trash bins most beaches today are filled with micro plastic and cigarette butts that stay intact for decades.
Powered Hang Gliders are the latest threat to nesting shorebirds and impossible to regulate
Photo: Carol Devillers
Plovers consist of about three dozen species with seven native to the US. Those are the Piping, Wilson’s, Snowy and Semipalmated Plover to the larger Killdeer, American Golden and Black-bellied Plover. One of the most interesting characteristics about plovers is that their chicks are born able to feed themselves. Plover parents don’t feed their chicks but they do guard them from predators. Males guard the territory from intruding males and potential predators.
Like the Killdeer, which look like a larger version of them, the Semipalmated Plover employs the ‘broken wing’ display hoping to draw predators away from the nest or chicks. They lay on the ground with wings spread as if injured, a predator thinks this is easy prey and swoops in for a closer look. The male then takes off leading the threat on a chase. Their diet consists of spider, flies, beetle, plant seeds and horseshoe crab eggs. Their population is currently considered sustainable.
In contrast the Piping Plover is listed on the US Endangered Species list with a global population of about 8,000 birds left. That may sound like a lot but it’s not and without immediate protection of nesting habitat their population could plummet. Their diet consists more of water beetles, snails and small crustaceans. They blend into the sand with their paler colorings and can be hard to spot. Plovers don’t nest in colonies like other shorebirds so when walking on the beach in summertime be aware there might be a tiny pair nesting. If you see a bird dive bombing you or hear loud squawking they probably have chicks or eggs nearby and are warning you not to get too close.
Semipalmated Plover in breeding plumage
Piping Plover non breeding
Next time you’re out on the beach please be mindful not to throw your trash anywhere but a closed and secure trash bin. Pick up any trash you find along the way especially plastic and cigarette butts. When visiting an active colony keep your distance and don’t stay too long. Remember if things were reversed you wouldn’t want strangers staring at you or your kids all day either. Enjoy watching them and help keep their home as free of trash as you would like to keep yours
If you would like to help save our shorebirds click on the link below to learn how/where you can volunteer or assist with rooftop nesters
If you think you have an active rooftop colony of nesting shorebirds please contact the Audubon Florida Rooftop Coordinator in your area immediately by email (contacts below) or contact us at FLConservation@audubon.org.
Also published on Emagazine June 28, 2022
Also published on The good men project on July 12, 2022