At the heart of the island grows a grows a small and stunted mangrove forest and an apicum, or wetland that only floods during lunar tides or spring tides. These are the highest of the monthly cycle of tides but only occur on the full and new moon. Every day the tide moves in and out of this small system. Twice a month the tide floods the apicum for several days at a time.
Here the tidal flow is gentle because the island shields it from the wind tossed Atlantic from all sides except the leeward quarter of the island. This gentle tidal flow flushes sediments from the mangrove swamp, the nutrients of the apicum and the normal productivity of a sediment-rich sandy substrate, forming the base layer of a productive food chain that nurtures small clams and other invertebrate – all prey for shorebirds.
We found whimbrels, semipalmated sandpipers, ruddy turnstones, short-billed dowitchers, black belly plovers, willets, semi-palmated plovers, sanderlings and collared plovers. In the lower reaches, we found 337 knots, a glorious find that will help our mapping model enormously.