Least Terns are the only species of tern that breed in Collier County, but they are not the only species of tern that can be seen on Sand Dollar, especially on mudflats on the lagoon side.
Royal Terns breed elsewhere in Florida, but some non-breeding individuals spent their summer in Collier County. Now more are arriving from their breeding grounds, including fledglings. The adults can be recognized by their large orange bills. The bird on the left in this photo is a juvenile that hatched this year. The other two are adults in their winter plumage.
These are Sandwich Terns in their winter plumage. Like the Royal Terns, they breed elsewhere in Florida and will winter here. To remember how to identify them, just associate “sandwich” with “mustard” and think of the yellow tip on their bills. The pictured birds are adults in winter plumage, while the young of the year will have some speckling like the juvenile Royal Tern.
If you are watching a flock of terns, you can try to pick out the fledgling-parent duos: an adult with a fledgling standing very close by. Some young birds are still hanging around their parents and begging in the hunched-up posture. The really insistent ones also “nag” their parents by cheeping at them. It’s comical to watch the parent birds ignore–or try to ignore–the chicks.
Other species of shorebirds are starting to return as well, including Laughing Gulls, Western and Least Sandpipers, Willets, and Snowy Plovers. They add variety and interest to the end of the nesting season and can be seen at the lagoon and on the Gulf. More on them later!
The rest of the sections of the photos page are complete! There are now photos of all stages–eggs through adults–of all three nesting species, plus pictures of stewards in action.
Following another weekend of stewarding which saw several of our regulars return from trips, I finally started adding photos to our “Photos” page (see the black menu bar just below the picture of the Black Skimmers). First up: stewarding photos. Next: each of our three species of nesting birds for 2010.
If you have better photos of stewards stewarding, send them in!
On sunny days, you will probably notice that many of the terns and skimmers at the colony are sitting or standing around with their mouths open. If you get a good look at a chick, you will notice they, too, spend a lot of time gaping. Here are an adult Black Skimmer and a Least Tern chick demonstrating this behavior.
Birds do this to keep cool. Opening the mouth increases exposed surface area, which increases heat dissipation. Every little bit of cooling helps, since on a typical day in south Florida, surface temperatures on the beach can exceed 120 F.
Shorebirds use other methods to keep cool. Most obviously, they seek whatever shade they can find, including the sliver of shadow cast in a footprint. The adults also shade both eggs and chicks. Studies with Common Terns have found that eggs left unshaded on a hot day can become unviable in less than 10 minutes. In addition, young chicks are not capable of regulating their own body temperatures until they are a few days old, so adults attend them diligently. That’s why the adults’ presence at the nest scrape or with their chicks is so important, especially in a climate like ours.
Least Terns use a behavior called belly soaking to cool their eggs and chicks off. They briefly land belly-down in the water to get their feathers wet, then return to the nest and drip on their young. Finally, when the chicks get older, they can move around more to find shade. Tern and skimmer chicks both like to huddle under bushes or in the shade of a scarp, while skimmer chicks in particular will move down to the waterline with their parents to take advantage of the cooler temperatures and wet sand.
Today there is lots of sea pork washing up on the Marco Island beach–flesh color, bright orange and black. The black is being mistaken for tar balls.
How can you tell the difference between sea pork and a tar ball? Sea pork will be firm, smooth, rubbery and flexible and smells a bit like algae or “low tide.” If you look closely, you can actually see the tiny individual zooids embedded in the cellulose “glob.” Tar bars will be sticky and distinctly smell like hydrocarbon, asphalt or oil.
Pass the word along to fellow stewards and any beach-goers who have questions!
Posted in Natural History
As the nesting season draws down, you may notice that there seems to be fewer adults and fledglings to be seen on Sand Dollar. At first the reason for this is that once they have finished nesting for the season, adults and fledglings may leave the colony and disperse around the county to other feeding and roosting sites. They will then spend the next several weeks fattening up and improving their body condition–raising a brood of chicks is very demanding work–and the year’s young need to learn to become proficient hunters so they can feed themselves. After they have fueled up, our nesting shorebirds will depart the area and head to their wintering grounds. Where do they go?
Least Terns winter in Mexico, the Caribbeean, Central America, and northern South America. Individuals that breed in New England have quite a long flight before them! No one knows for sure exactly where our southwest Florida population of terns winters.
Black Skimmers from northern states like New York may migrate only as far south as Florida, while more southern populations depart for the Caribbean or Central America or choose to stay put on or near their breeding grounds.
Wilson’s Plovers follow a similar pattern, often wintering in the Caribbean, Central America, or South America, although unlike the Black Skimmer and the Least Tern, they do not breed as far north.
The next lunchtime get-together for stewards will be at 1:30 this Sunday, August 1, at Pelican Bend on Isles of Capri. If you haven’t been, it has indoor and outdoor seating and it’s on the water. Overall, a great spot. You don’t have to have stewarded on that day to participate, so if you’d like to meet some more of your fellow stewards, stop by!