Location and General Description
This ecoregion is distributed throughout the northern Bahamas Islands including coverage on the eastern third of Andros Island and Abaco, Andros & Grand Bahama Islands also have large tracts of dry forest The Bahamas, with a land area of 11,400 km2, comprises over 2,750 islands, cays and rocks. Although the size of The Bahamas is traditionally estimated by its landmass including many small, uninhabited isles, this whole of this country actually extends over a marine territory of about 160,000 km2. The islands and cays are low-lying, with an average elevation of only 10 m. Although, many have low hills that reach 30-60 m in height. The dominant vegetation is low, dense, and thorny except on many of the northern Bahamian Islands where trees can get quite tall. Almost every island contains some wetland habitat, with the great majority comprising shallow brackish to saline lagoons, mangrove swamps, coastal flats and inter-tidal mudflats (Scott and Carbonell 1986). Across the Turks-Caicos Islands (~500 km2) these dry forests are distributed fairly evenly. Habitat in the Turks-Caicos Islands consists primarily of an understory of scrub bush and cacti covered by a low tree canopy. The Islands have a relatively unproductive, sandy topsoil that supports sparse vegetation of sedge and cacti. Scrub-type forest has been estimated to cover about 90% of the total land area of the Turks-Caicos Islands (Procter & Fleming 1999). These forests are also considered broad-leaf hardwoods that grow on limestone soil and include some of dominant tree species such as maderia or Caribbean Mahogany (Swietenia mahagoni), and Gum-elemi or gum-limbo (Bursera simaruba).
Most extant mammals in this ecoregion are introduced. Mammals that are endemic to this dry forest ecoregion include the Bahamian hutia (Geocapromys ingrahami), and the funnel-eared bat (Natalus tumidifrons). Many of the bird species are suffering declining population numbers due to habitat loss and illegal hunting for foreign collectors or by farmers for crop protection however the Bahamas yellow-throat (Geothlypis rostrata), the Bahamian race of the Rose-throated Amazon parrot (Amazona leucocephala bahamensis), and the Bahama woodstar (Philodice evelynae) are endemic birds found in The Bahamas. Inagua National Park on Great Inagua Island is the site of one of the world's largest colonies of wild, breeding West Indian flamingos (Phoenicopterus ruber). In 1959 there were about 2000 birds left confined to three islands. Today there are over 60,000 flamingoes in four colonies including a large colony on Lake Rosa and Great Inagua then smaller colonies on Acklins, Crooked, and Caicos Islands. Flamingos, however, do not specifically live in dry forests but are associated due to the dry forests that surround the large saline lagoons & coastal estuaries.
The xerophytic forests in this ecoregion provide suitable habitat for West Indian rock iguanas. The Bahamas are therefore home to four endemic iguana species including the Andros Island iguana (Cyclura cychlura cychlura) the Exuma Island iguana (Cyclura cychlura figginsi), Allen’s Cay iguana (Cyclura cychlura inornata), Bartsch’s iguana (Cyclura carinata bartschi), the White Cay iguana (Cyclura -rileyi cristata), the San Salvador iguana (Cyclura rileyi rileyi) and Acklins Iguana (Cyclura rileyi nuchalis). The rock iguanas are endangered throughout The Bahamas because of habitat loss, illegal capture for pet trade, and predation of nests and juveniles by introduced mammals such as rats, cats, and others. A survey of the endemic Turks-Caicos ground iguana (Cyclura carinata carinata) undertaken in 1995 found over 50,000 individuals but are now estimated at 15, 000 individuals and listed as critically endangered on the IUCN Red List. On nearly every island in the Turks-Caicos Islands within this ecoregion, where domestic animals occur, iguanas are absent. Big Ambergris Cay is the largest island refuge for the endemic iguanas, supporting more than 50% of the total estimated population (Procter 1999).
Agriculture among the Caribbean nations within this dry forest ecoregion has dominated land-use patterns resulting in major changes to terrestrial habitats and a reduction in biodiversity. Centuries of deforestation and land clearing have resulted in the removal or alteration of much of the original vegetation and contributed to a subsequent loss of species richness (CCA 1991).
The Bahamas National Trust holds and manages lands, waters and places of natural beauty or historic interest for the purposes of conservation and preservation. The Wild Birds Protection Act of 1905, revised in 1972, makes provisions for the designation of areas protected from hunting through the creation of Wild Bird Protection Reserves. Between 1951 and 1965, 11 orders were passed designating 25 areas as wild bird reserves. The Turks and Caicos National Trust was established as a statuary body in 1992 to help to preserve the biodiversity and cultural heritage of the Islands. The aim was to establish an effective managerial framework for local and international fund-raising, a public awareness and educational program, and a legal framework for conservation of sites. Much of the initiative and impetus for environmental protection and conservation in the Islands has come from non-governmental organizations. Considerable progress has been made in the designation of protected areas. Steps have been taken to implement an overall plan for national parks. Regulations have been drafted for the management of national parks with financial assistance from the UK government.
Types and Severity of Threats
In the perpetual quest for economic advancement, natural resources in vast areas of The Bahamas and the Turks-Caicos Islands have been heavily exploited. Dry forests have been destroyed or altered as a result of valuable timber and bark cutting, development of plantations with monocultures and introduced livestock, and slash and burn agriculture. At the same time, the introduction of alien flora and fauna, urban sprawl, and the development of a vast tourism infrastructure have taken a profound toll on the native biodiversity of this ecoregion. Matured forest stands are rare in many places because of the high demands for fuelwood and charcoal production (CDB 1983). Many faunal species are endangered due to collection for sale in the pet trade and by destruction of their natural habitat. The main pressure on existing protected areas comes from illegal hunting and fishing as it is the case for the two largest areas in The Bahamas (Inagua National Park and Exuma Cays Land-and-Sea Park). Additionally, most protected areas face an overuse from tourism and a lack of efficient management (OAS 1988). Overshadowing these problems is a broader indifference to the dramatic population growth and the lack of a broad conservation ethic (Raffaele et al. 1998).
Justification of Ecoregion Delineation
The dry forests of the Bahamas and Turks and Caicos Islands host a number of endemic species, and distinguishable from all nearby dry forests by distinct species assemblages. Linework for this ecoregion follows Brown et al. (1998) who classify this as Caribbean Dry Forest.
Anon. 1991. Policy Statement for National Parks. Bahamas National Trust, Nassau.
Brown, D.E., F. Reichenbacher, and S.E. Franson. 1998. A classification of North American biotic communities. University of Utah Press, Salt Lake City, Utah, USA. 141 pp.
CCA. 1991. Environmental agenda for the 1990’s: A synthesis of the eastern Caribbean country environmental profile series. Caribbean Conservation Association and The Island Resources Foundation. Bridgetown. Barbados.
CDB. 1983. Regional Forestry Sector, Country Study Report, Turks and Caicos Islands. Caribbean Development Bank, Barbados.
IUCN. 1992. Protected areas of the world: a review of national systems. Volume 4: Nearctic and Neotropical. IUCN, Gland, Switzerland and Cambridge, UK.
OAS. 1988. Inventory of Caribbean Marine and Coastal Protected Areas. Organization of American States, Department of Regional Development. In C. Ray, editor, (1961), Report of the Exuma Cays park project. Bahamas National Trust.
Procter, D., and L. V. Fleming, editors. 1999. Biodiversity: The UK overseas territories. Peterborough, Joint Nature Conservation Committee.
Raffaele, H., J. Wiley, O. Garrido, A. Keith, and J. Raffaele. 1998. A guide to the birds of the West Indies. Princeton University Press. Princeton.
Scott, D.A. and M. Carbonell. 1986. Directory of Neotropical Wetlands. IUCN, Cambridge and IWRB, Slimbridge.
Prepared by: Sean Austin
Reviewed by: Ann Sutton