The pristine wetlands of Little Cayman comprise 1,100 (40%) of the island' s area. The Crown Wetlands cover ha and occur as four types:1. On the north and south coasts, the 'mangrove' wetlands, each associated with a hypersaline lagoon, are Easterly Pond (3 ha), Rosetta Flats Pond (2 ha), Sandy Point Pond (3.5 ha), Tarpon Lake Complex (236 ha), Spot Bay Pond (5 ha), Jackson's Pond (9 ha) and Grape Tree Pond (10 ha). The fringe vegetation is of differing combinations of the four mangrove species mixed with Cordia sebestena, Thespesia populnea and Rhabdadenia biflora.2. In the south-west, Preston Bay westerly ponds (8.4 are brackish herbaceous wetlands on pavement ironshore; the vegetation is Conocarpus, Laguncularia, Acrostichum aureum and herbaceous species Sesuvium portulacastrum, Salicornia bigelovii, Ruppia maritima and Rhachiallis americana.3. An inland wetland on the eastern bluff, Charles Bight Pond (8.5 ha) with monospecific Conocarpus sp.4. A temporary freshwater wetland, Coot Pond (0.1 ha), on the south-east coast; the vegetation is Conocarpus grassland.All wetlands dry out seasonally, except Tarpon Lake.
The site has up to 135 pairs of the globally threatened West Indian Whistling-duck, which is more than 1% of the global population, with the largest sub-populations at Jackson's Pond, Grape Tree Pond and Charles Bight Pond. A total of 16 taxa breed: White-crowned Pigeon, Zenaida Dove, Yellow Warbler and biome species Greater Antillean Grackle bangsi. This race is confined to Little Cayman, having become extirpated on Cayman Brac (around 1945) in the mangrove and migrant on pond edges. There is a mixed heronry of max 250 pairs of Snowy Egrets Egretta thula and Tricoloured Herons on Jackson's Pond; Yellowcrowned Night-herons (in small colonies or singly, with the highest numbers at Tarpon Lake, Jackson's Pond and Charles Bight Pond) and Green Herons (singly) breed throughout. Max counts are 16 pairs Pied-billed Grebes, 60 pairs Least Terns, 10 pairs Willets, 16 pairs American Coots,Common Moorhens, and 250 pairs of Black-necked Stilts. A major wintering site for up to 1,500 Blue-winged Teals, 60 Northern Shovelers, 32 American Wigeons and 64 Lesser Scaups, 300 American Coots, 83 Great Blue Herons, 160 Great Egrets, 360 Greater Yellowlegs and Lesser Yellowlegs, and 250 Semipalmated Sandpipers and Least Sandpipers. Purple Gallinules Porphyrio martinica, Soras and Wilson's Snipe Gallinago delicata occur on Coot Pond and the Preston Bay westerly ponds. Migrant raptor species include Osprey, Merlin and Peregrine Falcon. Regular migrant landbirds, mainly warblers, include most commonly Northern Parula, Yellow-throated Warbler, Palm Warbler, Prairie Warbler, Black-and-white Warbler, American Redstart, Ovenbird andNorthern Waterthrush.
Non-bird biodiversity: Endemic reptiles as KY001. Other important species are Cardisoma guanhami and Barbouria caymanensis.
BirdLife International (2023) Important Bird Areas factsheet: Crown Wetlands. Downloaded from http://www.birdlife.org on 30/01/2023.