Trinidad and Tobago is the southernmost island country in the Caribbean. It is known for its fossil-fuel wealth. Consisting of the main islands Trinidad and Tobago, and numerous much smaller islands, it is situated 130 kilometres south of Grenada and 11 kilometres off the coast of northeastern Venezuela. It shares maritime boundaries with Barbados to the northeast, Grenada to the northwest and Venezuela to the south and west. Trinidad and Tobago is generally considered to be part of the West Indies. According to some geographic definitions, Trinidad and Tobago are also part of the Windward Islands and Lesser Antilles, while other definitions regard Trinidad and Tobago as a separate island group.
Because Trinidad and Tobago lies on the continental shelf of South America, and in ancient times were physically connected to the South American mainland, its biological diversity is unlike that of most other Caribbean islands, and has much more in common with that of Venezuela. The main ecosystems are: coastal and marine forest; freshwater karst; man-made ecosystems and savanna.
Information about vertebrates is good, with 472 bird species, about 100 mammals, about 90 reptiles, about 30 amphibians, 50 freshwater fish and at least 950 marine fish. Notable mammal species include the ocelot, West Indian manatee, collared peccary, red-rumped agouti, lappe, red brocket deer, Neotropical otter, weeper capuchin and red howler monkey; there are also some 70 species of bat, including the vampire bat and fringe-lipped bat. The larger reptiles present include 5 species of marine turtles known to nest on the islands' beaches, the green anaconda, the Boa constrictor and the spectacled caiman. There are at least 47 species of snakes, including only four dangerous venomous species, lizards such as the green iguana, the Tupinambis cryptus and a few species of fresh water turtles and land tortoises. are present. Of the amphibians, the golden tree frog is found only in the highest peaks of Trinidad's Northern Range and nearby in those of Venezuela's Paria Peninsula. Marine life is abundant, with several species of sea urchin, coral, lobster, anemone, starfish, manta ray, dolphin, porpoise and whale shark present in the islands' waters. The introduced Pterois is viewed as a pest, as it eats many native species of fish and has no natural predators; efforts are currently underway to cull the numbers of this species. The country contains five terrestrial ecoregions: Trinidad and Tobago moist forests, Lesser Antillean dry forests, Trinidad and Tobago dry forests, Windward Islands xeric scrub, and Trinidad mangroves.
Trinidad and Tobago is noted particularly for its large number of bird species, and is a popular destination for bird watchers. Notable species include the scarlet ibis, cocrico, egret, shiny cowbird, bananaquit, oilbird and various species of honeycreeper, trogon, toucan, parrot, tanager, woodpecker, antbird, kites, hawks, boobies, pelicans and vultures; there are also 17 species of hummingbird, including the tufted coquette which is the world's third smallest.
Information about invertebrates is dispersed and very incomplete. About 650 butterflies, at least 672 beetles and 40 corals have been recorded. Other notable invertebrates include the cockroach, leaf-cutter ant and numerous species of mosquitoes, termites, spiders and tarantulas.
Although the list is far from complete, 1,647 species of fungi, including lichens, have been recorded. The true total number of fungi is likely to be far higher, given the generally accepted estimate that only about 7% of all fungi worldwide have so far been discovered. A first effort to estimate the number of endemic fungi tentatively listed 407 species.
Information about micro-organisms is dispersed and very incomplete. Nearly 200 species of marine algae have been recorded. The true total number of micro-organism species must be much higher.
Thanks to a recently published checklist, plant diversity in Trinidad and Tobago is well documented with about 3,300 species recorded. Despite significant felling, forests still cover about 40% of the country, and there are about 350 different species of tree. A notable tree is the manchineel which is extremely poisonous to humans, and even just touching its sap can cause severe blistering of the skin; the tree is often covered with warning signs. The country had a 2019 Forest Landscape Integrity Index mean score of 6.62/10, ranking it 69th globally out of 172 countries.
Threats to the country's biodiversity include over-hunting and poaching, habitat loss and fragmentation, water pollution, and introduction of invasive species and pathogens.