Country: Turks-Caicos Is.
Administrative region: Big Ambergris Cay (Island)
Central co-ordinates: 21.30147 N, 71.63272 W
Area: 4.37km²
Qualifying IPA Criteria
A(i)Site contains one or more globally threatened species, B(ii)Site contains an exceptional number of species of high conservation importance, B(iii)Site contains an exceptional number of socially, economically or culturally valuable species, C(iii)Site contains nationally threatened or restricted habitat or vegetation types, AND/OR habitats that have severely declined in extent nationally
IPA assessment rationale
The whole island of Big Ambergris Cay is designated as a TIPA due to meeting multiple criteria. It qualifies under A(i) for threatened species as it is estimated to support more than 5% of the national population of the threatened shrub Argythamnia argentea. It is also one of the five best sites for Encyclia caicensis and is estimated to support more than 1% of the global population of Spermacoce brittonii. The site is botanically rich and meets criterion B(ii) by containing 13 species (more than or equal to 15%) from the list of species of high conservation importance, and criterion B(iii) by supporting 19 species (more than or equal to 15%) from the list of species of social, cultural or economic importance. Finally, Big Ambergris Cay also qualifies as a TIPA under criterion C(iii) through being one of the five best sites in Turks and Caicos for the threatened herbaceous dune habitat.
Site description
This TIPA, comprising the entire island of Big Ambergris Cay, is situated far to the south-east of the main Caicos Islands archipelago. It is approximately four miles in length and one mile wide. It excludes the end of the airport runway, which was artificially constructed.
Botanical significance
This island supports populations of at least four globally threatened species. These species are the orchid Encyclia caicensis, the Lucayan endemic shrub Argythamnia argentea, the shrub Chamaecrista caribaea and the endemic shrub Spermacoce brittonii. Historical records of two further threatened species, Lepidium filicaule and Ayenia tenuicaulis are also known from this island, but no contemporary records are known so the continued presence of these species here is uncertain. 12 species of high conservation importance are also found here such as the Lucayan endemics Agave inaguensis, Coccothrinax inaguensis and Euphorbia gymnonota. It is the most important site nationally for the Turks Head Cactus Melocactus intortus, a plant of high cultural importance due to its designation as the national plant. Also of particular significance to this TIPA, are several species such as Sarcomphalus taylorii and Argythamnia argentea, which form an important component of the diet of the endemic Turks and Caicos Rock Iguana Cyclura carinata subsp. carinata), which is now only found on a small number of islands, including Big Ambergris.
Habitat and geology
This TIPA contains a diverse mix of habitats, though predominating is scrub and limestone thicket, interspersed with upland grassland (a habitat maintained by grazing by the TCI Rock Iguana). Dwarf shrubland is found across the island. It is a rocky, dry and sun-exposed habitat, critical for cacti species Melocactus intortus and Mammillaria nivosa. The eastern coastline comprises iron-shore, sediment-shore, coastal scrub and herbaceous dunes, the latter for which Big Ambergris is one of the five best sites in Turks and Caicos. Herbaceous dunes are important sites for salt and drought-tolerant plants and they are also a preferred habitat for the TCI Rock Iguana. On the western shore, estuarine habitats, palustrine marsh and swamplands are common.
Conservation issues
The cay is a resort island with risks to biodiversity from further development (buildings and roads) and the potential introduction of domesticated animals. The island is being proposed as an Important Bird Area due to containing the largest breeding population of Roseate Terns in TCI. In conjunction with its designation as a TIPA, it therefore has potential to be a Key Biodiversity Area.
Site assessor(s)
Assessed by:
Bryan Naqqi Manco, Department for Environment and Coastal Resources, Turks and Caicos Government
Junel Blaise, Department for Environment and Coastal Resources, Turks and Caicos Government
Dodly Propser, Department for Environment and Coastal Resources, Turks and Caicos Government
Amy Barker, Royal Botanic Gardens, Kew
Sara Bárrios, Royal Botanic Gardens, Kew
Elloise Budd, Royal Botanic Gardens, Kew
Stuart Cable, Royal Botanic Gardens, Kew
Colin Clubbe, Royal Botanic Gardens, Kew
Marcella Corcoran, Royal Botanic Gardens, Kew
Thomas Heller, Royal Botanic Gardens, Kew
Juan Viruel, Royal Botanic Gardens, Kew
Tim Wilkinson, Royal Botanic Gardens, Kew
Date of first assessment: 14th Feb 2025
IPA criterion A species
| Species | Qualifying sub-criterion | ≥ 1% of global population | ≥ 5% of national population | 1 of 5 best sites nationally | Entire global population | Socio-economically important | Abundance at site |
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| Argythamnia argentea | A(i) |  |
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| Ayenia tenuicaulis | A(i) | |
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| Chamaecrista caribaea | A(i) | |
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| Encyclia caicensis | A(i) | |
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| Lepidium filicaule | A(i) | |
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| Spermacoce brittonii | A(i) | |
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| Zanthoxylum flavum | A(i) | |
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Argythamnia argentea
Qualifying sub-criterion:
A(i)
≥ 1% of global population:
≥ 5% of national population:
1 of 5 best sites nationally:
Entire global population:
Socio-economically important:
Abundance at site:
Ayenia tenuicaulis
Qualifying sub-criterion:
A(i)
≥ 1% of global population:
≥ 5% of national population:
1 of 5 best sites nationally:
Entire global population:
Socio-economically important:
Abundance at site:
Chamaecrista caribaea
Qualifying sub-criterion:
A(i)
≥ 1% of global population:
≥ 5% of national population:
1 of 5 best sites nationally:
Entire global population:
Socio-economically important:
Abundance at site:
Encyclia caicensis
Qualifying sub-criterion:
A(i)
≥ 1% of global population:
≥ 5% of national population:
1 of 5 best sites nationally:
Entire global population:
Socio-economically important:
Abundance at site:
Lepidium filicaule
Qualifying sub-criterion:
A(i)
≥ 1% of global population:
≥ 5% of national population:
1 of 5 best sites nationally:
Entire global population:
Socio-economically important:
Abundance at site:
Spermacoce brittonii
Qualifying sub-criterion:
A(i)
≥ 1% of global population:
≥ 5% of national population:
1 of 5 best sites nationally:
Entire global population:
Socio-economically important:
Abundance at site:
Zanthoxylum flavum
Qualifying sub-criterion:
A(i)
≥ 1% of global population:
≥ 5% of national population:
1 of 5 best sites nationally:
Entire global population:
Socio-economically important:
Abundance at site:
IPA criterion C qualifying habitats
| Habitat | Qualifying sub-criterion | ≥ 5% of national resource | ≥ 10% of national resource | 1 of 5 best sites nationally | Areal coverage at site |
|---|---|---|---|---|---|
| Herbaceous dune | C(iii) | |
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Herbaceous dune
Qualifying sub-criterion:
C(iii)
≥ 5% of national resource:
≥ 10% of national resource:
Areal coverage at site:
General site habitats
| General site habitat | Percent coverage | Importance |
|---|---|---|
| Forest - Subtropical/Tropical Dry Forest | |
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| Grassland - Subtropical/Tropical Dry Lowland Grassland | |
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| Marine Coastal/Supratidal - Coastal Sand Dunes | |
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| Wetlands (inland) - Permanent Saline, Brackish or Alkaline Marshes/Pools | |
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| Marine Coastal/Supratidal - Coastal Brackish/Saline Lagoons/Marine Lakes | |
Forest - Subtropical/Tropical Dry Forest
Percent coverage:
Importance:
Grassland - Subtropical/Tropical Dry Lowland Grassland
Percent coverage:
Importance:
Marine Coastal/Supratidal - Coastal Sand Dunes
Percent coverage:
Importance:
Wetlands (inland) - Permanent Saline, Brackish or Alkaline Marshes/Pools
Percent coverage:
Importance:
Marine Coastal/Supratidal - Coastal Brackish/Saline Lagoons/Marine Lakes
Percent coverage:
Importance:
Threats
| Threat | Severity | Timing |
|---|---|---|
| Residential & commercial development - Tourism & recreation areas | High | Ongoing - increasing |
| Invasive & other problematic species, genes & diseases - Invasive non-native/alien species/diseases - Unspecified species | Medium | Ongoing - increasing |
| Climate change & severe weather - Storms & flooding | High | Ongoing - increasing |
Residential & commercial development - Tourism & recreation areas
Severity:
High
Timing:
Ongoing - increasing
Invasive & other problematic species, genes & diseases - Invasive non-native/alien species/diseases - Unspecified species
Severity:
Medium
Timing:
Ongoing - increasing
Climate change & severe weather - Storms & flooding
Severity:
High
Timing:
Ongoing - increasing
Recommended citation
Bryan Naqqi Manco, Junel Blaise, Dodly Propser, Amy Barker, Sara Bárrios, Elloise Budd, Stuart Cable, Colin Clubbe, Marcella Corcoran, Thomas Heller, Juan Viruel, Tim Wilkinson (2025) Tropical Important Plant Areas Explorer: Big Ambergris Cay (Turks-Caicos Is.). https://tipas.kew.org/site/big-ambergris-cay/ (Accessed on 20/06/2025)