The site is composed of several small cays in the southern part of the Caicos Bank. These cays are therefore at the far side of the Bank from the main islands, which lie along the northern edge of the Bank. French, Bush and Seal Cays constitute Statutory Sanctuary 24. Fish and Little Ambergris Cays need Statutory Nature Reserve status but are nature reserves of the Turks & Caicos National Trust, on a 99-year lease from TCI Government to TCNT, who manage the sites.Fish Cay is a small rocky cay on the Caicos Bank between South Caicos and the Ambergris Cays.Little Ambergris Cay consists of several small cays surrounding a central lagoon, far removed from the larger cays of the Caicos Bank. An extremely long spit extends westwards from the Cay over the Bank.Bush and Seal Cays are small rocky cays near the south-eastern extremity of Caicos Bank. French Cay is a small sandy cay several kilometres to the west along the southern edge of the Caicos Bank.
The site is thought to hold on a regular basis more than 20,000 waterbirds and thus qualifies for A4iii status. The cays, primarily Bush Cay with some on Fish Cays, support breeding of a bio-regionally important population of the Bridled Tern (17%) .The cays hold internationally important breeding proportions of the global population of the Brown Noddy. Both French Cay and the Bush/Seal Cay group (the White Cays within the latter) support internationally important proportions in their own rights, with smaller numbers on Fish Cay. This area is therefore one of the most important regionally for this species.Fish Cay supports a bioregionally important proportion of the breeding population of Roseate Terns (300 individuals).Little Ambergris Cay is a resting and feeding area for Royal Tern (30 individuals), Sandwich Tern (200 individuals) and Roseate Tern. Small numbers of restricted-range and biome-restricted species also present.Bush and Seal Cays (with smaller numbers on the other cays) hold a significant proportion of the Caribbean breeding population of Sooty Terns.The Green-tailed Ground Warbler, a restricted-range species endemic to nearby Hispaniola, has been recorded on Bush Cay, which is the first land-fall from Hispaniola. It is the only recorded location in country.
Non-bird biodiversity: Internationally important species occurring on the site include the following Turks & Caicos Islands endemic species of lizard: Turks & Caicos Rock Iguanas Cyclura carinata carinata, Curly Tail Leiocephalus psammodromus, Caicos Islands Reef Gecko Sphaerodactylus caicosensis; and the one endemic species of snake: the Caicos Islands Trope Boa Tropidophis greenwayi. In addition there are further lizards that are endemic at the subspecific level: Turks & Caicos Bark Anole Anolis scriptus scriptus, and one snake: Bahaman Rainbow Boa Epicrates chrysogaster chrysogaster. The waters and reef are important for turtles Chelonia midas (EN), Eretmochelys imbricata (CR), Caretta caretta (EN), with important nesting beaches.
BirdLife International (2020) Important Bird Areas factsheet: Caicos Bank Southern Cays. Downloaded from http://www.birdlife.org on 25/02/2020.