Monday, February 10, 2014

Searching for the wintering grounds of the Piping Plover and other shorebirds

In CT, the U.S. Fish and Wildlife Service began monitoring Piping Plovers in 1986 when the species first received protection under the Endangered Species Act.  The CT DEEP Wildlife Division added their expertise with the passing of the Connecticut Endangered Species Act in 1989. The Audubon Alliance for Coastal Waterbirds joined the USFWS and the Wildlife Division in 2012.  With the help of an amazing group of volunteers, these organizations have been stewarding Piping Plovers and other beach-nesting birds along the CT shoreline for nearly 30 years.   Working together, staff, field technicians, and volunteers exclose nests, protecting them from predators; put up string fencing to reduce disturbance  in nesting areas; and engage beachgoers and municipalities by providing information about beach-nesting species, the threats they face, and how to help.   Through these efforts, the number of pairs of Piping Plover nesting in the state has slowly increased.

Protecting Piping Plover on their nesting grounds is very important to species recovery, but we also need to think about the species and the habitat it uses during migration and over the winter.  Until very recently little was known about the locations used by Piping Plover in winter.  The 2006 discovery of 400 Piping Plovers in the Bahamas by the National Audubon Society and the Bahamas National Trust triggered a closer look at the nation’s 700 islands and roughly 2,000 cays.  During the 2011 census, researchers found over 1,000 Piping Plovers--perhaps 20% of the entire Atlantic Coast population--concentrated in one small cluster of Bahamian islands--Andros Island, the Joulter Cays (now a globally Important Bird Area), and the Berry Islands. The census filled in a huge gap in our understanding of these engaging and imperiled birds.

This winter, National Audubon Society staff, from along the Atlantic Flyway and with support from the International Alliances Program, are pitching in to locate additional sites important to Piping Plover and other shorebirds in the Bahamas, including Audubon Alliance staff member, Corrie Folsom-O’Keefe. From Jan 14th – Jan 20th, Corrie joined Denny Moore of the Bahamas National Trust to survey the cays at the east end of Grand Bahama Island.  The pair traveled by flat bottom skiffs and on foot, inventorying shorebirds and other waterbirds on mudflats and along the edges of mangrove islands.   

Grand Bahama Island sits approximately 100 miles to the east of West Palm Beach, Florida.  At the east end of the Island, large cays stretch out to the southeast, with creeks flowing between them.

 “The tides around the cays played a role in where shorebirds could be found.” Corrie reported, “When it was high tide along the western side of the cays, it was low tide on the eastern side.  Under these circumstances, a mud flat, 3-4 acres in size, at the mouth of Rumer’s Creek hosted Black-belled Plovers, Semipalmated Plovers, and 150+ Short-billed Dowitchers.“

 “As the tide began to rise along the eastern side of the cays, the birds we saw at Rumer’s Creek moved to rocky areas along the shores of the cays or flats sparsely vegetated by young red mangroves along the edge of lagoons just beyond the shoreline.  We also found a flock of ~40 Short-billed Dowitchers perched on mangrove roots at Jacob Cay, a Double-crested Cormorant nesting colony. While at Red Shank Cay, Black-bellied Plover and Short-billed Dowitchers, Sanderlings, Semipalmated Sandpipers and a few Piping Plover roosted on an exposed sand bar four miles off shore from the larger cays.”  

                     Short-billed Dowitcher roosting on red mangroves on Jacob Cay.

At two areas on the western side of the cays, Big Creek and Thrift Harbor, shorebirds roosted on sparsely vegetated flats and a rocky island, respectively, directly adjacent to low tide foraging areas. “Every time we visited Thrift Harbor, we were able to find the shorebirds, a flock of ~100 Black-bellied Plover, Short-billed Dowitchers, Sanderlings, Ruddy Turnstones and Least Sandpiper, whether they were at their high tide roost spot or foraging on recently exposed rocky outcroppings.”

                     Sand flats at Big Creek Inlet.

“At Big Creek, on our second visit, Denny and I arrived just as the sand flats (2-3 acres) were appearing and watched Black-bellied Plover, Short-billed Dowitchers, and Semipalmated Plovers emerge from hiding places within the mangroves.”  A flock of 276 Least Sandpiper, several Wilson’s Plover, a few Sanderlings and Piping Plover could also be found at Big Creek at low tide. We suspect the flock of Least Sandpiper roosted on a lagoon on the interior of one of the cays, as we were unable to locate them at high tide along the shores.

   Least Sandpiper nestled amongst the rocks.

     Piping Plover foraging on the sand flats. 

One spot on the West side, Rocky Point, was a mecca for Short-billed Dowitchers at low tide.  “We counted 488 actively foraging on a mud flat along with some Black-bellied Plover and Semipalmated Plover, which was exposed for maybe an hour or two.  It was a spot we had visited a few times already, but not at low tide.  Thank goodness we decided to wait for the water level to drop.”  

“A question we had about the birds at Rocky Point was: Where did they come from?   On our final day of surveying, Denny and I got to Rocky Point for mid-tide.  We found a flock of about 30 Semipalmated Plover preening along the shore, then had our Guide drop us off on Brush Cay about half a mile to the South and in the direction we observed the Short-billed Dowitchers come from the day before.” 

About an hour passed and then suddenly a huge flock appeared between Brush Cay and Rocky Point.  The birds swirled above Rocky Point (possibly hesitant to land with fisherman in the area), then flew over Brush Cay and headed out in the direction of Red Shank Cay.  “We are pretty certain that had the flock come from Red Shank or Barrow’s Cay, even further to the South, we would have seen them flying in from that direction. Based on where we first caught sight of them, it seems more likely that they came from the eastern side of the cays. We suspect that some of the birds of East Grand Bahama, take advantage of the tides and travel from one side of the Cays to the other to forage on exposed mud and sand flats every 6 hours versus every 12 hours.“

“Over the course of the five days we spend in East Grand Bahama, Denny and I were able to locate 526 Short-billed Dowitcher (possibly enough to qualify the area as a continentally Important Bird Area), 276 Least Sandpipers, 148 Semipalmated Plover, 50 Sanderling, approximately 75 Black-bellied Plover, 20 Ruddy Turnstone, 12 American Oystercatchers, between 7-14 Piping Plover, and 6 Wilson’s Plover. 
                      Ruddy Turnstone resting on a conch shell.

The data not only increases our knowledge of shorebird wintering habitat but also will be used by the Bahamas National Trust to determine whether the area should be designated as a National Park. “We also documented a Brown Pelican nesting colony, three Double-crested Cormorant nesting colonies, and the presence of Magnificent Frigate Bird and Common Merganser. 

 Lastly, the area provided ample habitat for herons and egrets; we located a spot with 14 Tri-colored herons and suspect this may have been a nesting site for the species. “   

“Surveying for shorebirds on their wintering grounds in East Grand Bahama was an awesome opportunity and I look forward to sharing my stories while on the beaches of CT this summer.”

Corrie Folsom-O’Keefe

Audubon Alliance for Coastal Waterbirds

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