by Ted Below
Although the west coast of Florida is said to be a low energy coast; this does not mean that it is a no energy coast. The coast is continually changing, especially the sand shoals around coastal inlets and around large geographical features such as the Marco Inlet and Cape Romano. The natural changes have dramatic effects on coastal nesting birds, but when you add the activities of homo sapiens, the results are more than impressive, as seen below.
After the beach renourishment on Marco Island in 1990 that pumped sand from both the passes at the north and south ends of the island, Least Tern nesting almost completely ceased. The ephemeral sandbars near both passes changed dramatically; the northern sandbar just off Tigertail Beach, sometimes known as Sand Dollar, almost disappeared and the southern sandbar at Caxambas Pass that had no name completely washed away.
The loss of this major Least Tern nesting habitat caused a considerable decline in nesting in the area for five years. In 1996, Sand Dollar had built back up and there were good numbers of Least Tern nests (335), most of them in the areas closed off and protected by the Florida Fish and Wildlife Commission (FWC). Because of a lot of human disturbance outside the closed areas, the Least Terns were not very productive. [Note: The closed areas only encompass a small part of the sandbar, people and beach patrolling vehicles just outside the closures, can and do go very close to the nesting birds, this causes considerable flushing and thus low breeding success.]
In 1997, the Least Terns again set up on Sand Dollar in the closed area (386 nests) and had similar problems, but there was a difference. Just after egg laying most of the nests were deserted. Several days after we (my wife Ginny and I) recorded this nest abandonment, we were censusing a small sandbar near Morgan Point , Cape Romano (seven miles south of Marco Island), we recorded 42 Least Tern pairs starting to nest and I said to my self "they are looking for a second chance." The nesting was not very successful with the same problem as Sand Dollar, people disturbance.
At one time (1979) this was a large sparsely vegetated sandbar that eroded and stayed submerged until 1995 when it started to push up again. By 1997, at high tide the sandbar was crescent shaped, about 200-300 yards long and a couple of feet high. At the time I knew that most of Cape Romano Island was managed by the State of Florida, Department of Natural Resources, Rookery Bay Research Reserve (RBRR) but did know who was responsible for the sandbar. Mentioned the nesting to Gary Lytton, manager of RBRR, and not only did he tell me that the RBRR was responsible for the bar but he asked me what I thought about protecting it. I told him that I thought it was too late for 1997, but that we ought to jump on closing the nesting area next year, when the terns started to show interest.Then said that it would be necessary to close the nesting site right to the low tide line to keep people away from the breeding birds and that more informative signage was needed.
Early in 1998, the responsibility for the project was given to one of the state staff (B. Anderson) and she contacted me and wanted first of all to know what to call the sandbar. I responded with "2nd Chance." We then discussed methods and timetable.
The terns came back in early April right on schedule. Rookery Bay Research Reserve staff (6-7) with several boats, stakes, signs, string and flagging accomplished the closure just as the Least Terns started scraping nests (many sand nesting birds do not actually build nests but scrape depressions in the sand to nest in). The closure on the northern one third of 2nd Chance worked quite well and had 122 nests that produced at least two chicks per nest (very good), at the same time Sand Dollar had 161 nests that hardly produced a chick.
Since that time the numbers of unproductive nests on Sand Dollar have gone down and the numbers of very productive nests at 2nd Chance have gone up. The nesting at 2nd Chance has steadily increased and split into two areas, this has necessitated considerable more effort to protect the breed birds. Rookery Bay Research Reserve has done a great job, the two areas have been increased in size, the boundary signs have been driven right on the waters edge (as they often wash out this necessitates weekly visits to maintain the closure), and large "NO LANDING SIGNS" have been erected. This year almost the whole sandbar was closed and there were 497 Least Tern nests on 2nd Chance; Sand Dollar had 56.
June 12, there was an extreme high tide and strong wind event that caused over-wash of the nesting sites, this was the most critical time of the nesting season with eggs, small chicks and larger chicks all present in the two colonies. A good part of the eggs and small chicks were lost, some flying chicks were recorded near 2nd Chance; Sand Dollar had none. This shows that even with the best protection not every year will be productive, but at least now with the help of RBRR and boaters cooperation, Least Terns have a better prospect at 2nd Chance.
Post script: After the summer of 2002, 2nd Chance started to erode, by 2003 it was at least half gone and Least Tern nesting dropped considerably. By April 2004 the sandbar was over 90% gone, too low for nesting and Least Terns were back at Sand Dollar in good numbers. The FWC biologist has three large areas closed for the nesting; but the real question is whether they will have enough room, away from people to fledge chicks successfully? TB
First published in the Collier County Audubon Society's newsletter, Audugram, in November, 2002.