The Aripo Savannahs in eastern Trinidad are the last of the five natural Savannahs, the others being overtaken by human settlements. The flora includes many ground orchids, including Pogonia rosea, all of which are under threat. The Aripo Savannahs have been proclaimed a scientific reserve, but little has been done to preserve and manage them.

The Aripo Savannahs are an unusual formation in eastern Trinidad. The superficial layers of soil consist of a white quartz sand over an impervious layer of clay. In the wet season the Savannahs are inundated while there is extreme drought during the dry season. The flora consists mainly of species which can either do with minimum nutrients or are able to fix their own nitrogen, Insectivorous species such as sundew are abundant, as are ground orchids.

The butterfly plant, an orchid, Oncidium papilio, is prized by collectors. Consequently, numbers are declining. An attractive feature of the species is its flowering strategy. It produces a single flower at a time, a flower lasting about two weeks, but it may do this continuously over a period of up to two years. Floral form and movement of the flower at the end of the flower stalk does convey an illusion of a solitary butterfly.

In addition to the native flora the islands have an introduced flora of agricultural and horticultural species which have established themselves in the wild. The common black stick, Pachystachys coccinea, of cocoa plantations is one. It is favoured by hummingbirds.

We think of cacti as terrestrial desert dwelling succulent species. There are several epiphytic cacti in Trinidad and Tobago. Helocereus, a night blooming species, produces numerous large flowers, the size of dinner plates, for a few nights in June each year. Bees are attracted to the flowers.

The largest family of plants to be found in Trinidad is the orchid, with about 200 species. The total flora amounts to about 2 500 species. The Monkey throat orchid, Coryanthes macanthra, produces a single short lived flower at a time. The flower is pollinated by euglossine bees attracted from great distances to the flower by its scent. The floral form is such as to force the bee to exit over the reproductive surfaces. The flower lasts about 24 hours. Charles Darwin first described pollination of the species.

The Nariva Swamp, in eastern Trinidad, is the largest freshwater wetland in the island. It is under considerable pressure from squatting, illegal rice farming, and marijuana cultivation. It is a major refuge for several threatened species of birds and mammals. Community types vary from open areas to palm and swamp forests. To survive in these conditions many trees develop buttressing.

Access to the Nariva Swamp is through a series of natural and man made channels. This view is of the Boat Canal leading west to the Bush Wildlife Sanctuary, established in 1968. In the distance are the palm and swamp forests of the Sanctuary.

In spite of development, there is a range of forest types still to be found in Trinidad and Tobago. However, elfin woodland or cloud forest is unusual and confined to the summits of El Tucuche and Cerro del Aripo, at elevations of over 900m. Continuous cloud and moisture have stunted trees and mosses. Bromeliads and palms dominate.

There are many waterfalls in the Northern Range. The Maracas Waterfalls are at the head of the Maracas Valley and measure about 100 m. The noted Trinidadian artist of the Victorian era, Cazabon, painted these falls. Flow varies from a spray in the dry season to a deluge after heavy rains.

The fauna of Trinidad are dominated by insects and taxonomists still find undescribed species. The alligator bug or snout is a rare species of the Fulgoridae family. Its unusual head gives the impression of the head of an alligator.

This tiger beetle, a common element of the forest fauna, is one of the largest in Trinidad. It often comes to the lights of homes in forested areas at night, and although not particularly aggressive, are capable of inflicting painful wounds with its powerful jaws.

The iguana is a common inhabitant of urban and suburban gardens, as well as open spaces and secondary forest. It Is particularly common on the offshore islands, and is an able swimmer. It is herbivorous, feeding on buds and flowers, and is hunted for its flesh.

One of the most unusual amphibians in Trinidad is the leaf nest building frog, Phyllomedusa tarsier, a moderately common dweller of bushes and secondary scrub. There are two striking features of this species. One is that it has opposable fingers and toes which enable it to move about small shrubs and bushes. The other is that it produces a nest of leaves of bushes overhanging ponds, into which the eggs are laid, the larvae falling on hatching into the water below.

Most authorities doubt the existence of true island endemic species in Trinidad, largely because of the proximity to the mainland, and the timing of the separation. The golden tree frog, Phyllodytes auratus, is possibly an island endemic species. It is found only in tank bromeliads at elevations above 900m in the Northern Range.

This minute nymph of a flattid bug is a common species found in epiphytic vegetation in forests. It is has two tufts of waxy anal scales which are erected into a fan when it is startled. Total length, including the scales, is about 8mm.

The Orinoco River has a pronounced effect on inshore conditions in Trinidad. Consequently coral reefs are not well developed in the Gulf of Paria. On the north coast of Trinidad, however, there are several patch reefs and one fringing reef at Salybia, Toco. The Salybia reef is not well known because of its exposure to wave action which makes it dangerous for diving. The crest of the reef is nevertheless well known, and is dominated by a framework of finger coral, supporting a rich algal and invertebrate community.

Possibly the most rare of the Trinidad frogs is Rana palmipes, the only representative of the genus Rana to be found in South America. It is know in Trinidad from only five specimens, all collected from forested areas. It is a fairly common species on the adjacent mainland. As may be expected, it does not have a local name.

A picture of cooperation are these geometrid or inch worm caterpillars feeding on the edge of a leaf Their size dictates that they cannot attack the surface and consequently have to feed on the edge. In order to do this they arrange their bodies to accommodate all.

Trinidad's largest snake is the anaconda or houilla, Eunectes murinus, measuring up to about 4m. It is mainly aquatic is found only in the Nariva Swamp. Continued clearing and draining of the swamp places this species at great risk.