Shorebird nesting season not as active as previous years
Although the shorebird nesting season was not as successful as years past, the Sanibel-Captiva Conservation Foundation shorebird program coordinator said they were able to band a half a dozen adults this year giving them the ability to locate them throughout the season.
“The cool thing that I have learned out of all of this . . . I actually went up to Longboat Key last week with my intern before he left and the beach looks really similar to Sanibel beach,” Sanibel-Captiva Conservation Foundation Shorebird Program Coordinator and Biologist Audrey Albrecht said.
That bit of information was interesting because one of SCCF’s banded snowy plovers went to Longboat Key this season where she laid a successful nest that hatched in July.
“I think next year I might start studying what habitat they are selecting when nesting,” she said.
The shorebird nesting season started later than any years that SCCF has on record. SCCF began monitoring snowy plovers in 2002 on Sanibel and Captiva and the last few years began monitoring Wilson’s plovers and least terns.
On April 19 the first snowy plover nest was found. Fourteen snowy plover nesting attempts were made this season with 10 nesting pairs.
Of the 14 nesting attempts, two were abandoned after the mates died.
“We had two incidences that a male plover was found sick and then brought to CROW and unfortunately did not survive. In both of those instances the female opted to abandon that nest. If the nest had been closer to hatching she might have stuck with it and tried to raise them. In both cases it was not very far along in incubation, so the female went ahead and abandoned it, found a new mate and tried to nest again,” Albrecht said.
Both of the females that had abandoned their nest were banded, which gave Albrecht the ability to track them. One revealed it had left after abandoning the nest.
“Last year, the same bird, orange black, when her nest failed she went over to Carlos Point and tried to nest again, the south bend of Fort Myers Beach,” she said. “I’m not sure if that is where she went this year because we didn’t get any resight.”
Four of the 14 snowy plover nests were washed over by the many storms in late May, early June that produced very high tides. Six other nests were depredated, mostly by crows. Albrecht said they identified crow tracks at the actual nest hole.
Two of the 14 nests made it to hatching. The one nest had three eggs, but Albrecht said they only saw one chick, which fledged successfully and is now banded.
“It will be interesting to see where that bird goes if it goes somewhere else to nest next year, or if it comes back to Sanibel,” she said.
Albrecht said she waits right before the fledgling is going to fly to band them.
SCCF started banding snowy plovers again in January. Prior to that, the snowy plovers were banded on Sanibel in 2009.
“We want to find out if Sanibel is a source, or a sink population. So that means if we are a source we are producing fledglings that are going to nest in other places. Or, a sink population, the birds come here to nest and they don’t successfully produce any young,” Albrecht said. “We are hoping that Sanibel has been, and will continue to be a source population, so our fledglings will successfully go off and nest elsewhere.”
This year six new snowy plover adults were banded, as well as one fledgling. The adults were banded before nesting season, providing some good data this season of where they went for their nesting destination.
“There was one original bird from the banding in 2009, she is still here and still nesting,” Albrecht said. “She just finally came back the other day, showed up at the Lighthouse. I don’t know where she has been since her nest failed here in May.”
A snowy plover, which is banded, that lives in the Panhandle is 17 years old. The Sanibel snowy plover is at least 9 years old.
The second nest that hatched had two eggs because it was a re-nest. She said later in the season when the snowy plovers are trying to re-nest they do not always produce a full three egg clutch, but rather one or two eggs.
Both of the two eggs hatched. The hatchlings survived for a few weeks before one disappeared and the other went missing a week after that.
Last year there were four snowy plover fledglings, compared to one this year. Albrecht said it seems as though they have experienced more storm events over the past two years causing wash overs, as well as an increasing number of crows causing more depredation.
Those numbers compare to 12 fledglings in 2011, seven in 2012, 19 in 2013, nine in 2014 and nine in 2015.
When nesting, snowy plovers look for wide open sandy beaches. Albrecht said they are looking for an area where they can blend in with the sand.
“They also like a small amount of vegetation, to provide shade,” she said. “They don’t nest too close to the dunes when given the choice because the tall dune vegetation makes it easy for predators to sneak up on them. They prefer to be out in the wide open where they can see all around them.
There were three nesting pairs of Wilson’s plovers utilizing the beaches, which was the same as last year. Albrecht said they had a total of five nesting attempts, two of which were washed over, another depredated by crows and two hatched producing four chicks.
“Three of those fledged,” Albrecht said.
The snowy plover that fledged, and the first Wilson’s plover that fledged, were both nests that hatched a day before a big storm impacted the island.
“They miraculously survived through the storm and made it to fledging, which is defeating the odds,” she said.
Some of the Wilson plovers fledglings are still hanging out on the west end of the island.
Although the Wilson’s plover likes the same nesting environment as the snowy plover, they often times seek out more vegetation.
The last shorebird SCCF monitors, least terns, arrived back on the islands in April, but they did not decided to nest here this year. Albrecht said the least terns are beginning to nest on gravel rooftops due to disappearing beach habitats. The gravel rooftops resembles their nesting habitat on the beach.
“We do have several active colonies in Lee County nearby. It is possible that the birds that did not choose to nest here they could have either gone to Fort Myers Beach where they did have a successful nesting colony, or they could have gone to some of those rooftops,” Albrecht said. “More than half of Florida’s least terns nest on rooftops.”
Albrecht said for those who see SCCF’s banded birds can email email@example.com with a picture of the shorebird if possible, a description of the colors seen on the birds legs and where it was found.
SCCF’s banded Sanibel birds have a metal band on their upper left leg and a single green band on the lower left leg. In addition, each bird, along its lower right leg have two different colored bands.
“That makes each of them individually identifiable,” Albrecht said.
In addition, individuals can post their sightings on the Florida Banded Bird Resightings Facebook page.
“It increases our ability to get the resights,” she said.
Although Sanibel’s nesting season is over, Albrecht said she is starting to see the fall shorebird migration beginning. Some of those include short-billed dowitcher, red knots, sanderlings and ruddy turnstones.