Frogs, toads, newts and salamanders are all amphibians, as they live underwater for at least some of their lives, and on land the rest of the time. Tobago is home to 15 different frog species, many of which are found inside the Main Ridge Reserve. Four of these are not found on Trinidad, and three are found nowhere else in the world.
The other astonishing thing about this species is how it reproduces. First, a male calls to attract multiple females to the underside of a carefully chosen Heliconia leaf by the side of a stream. A single male may mate with many females, each of which lays their eggs on the leaf before disappearing. The male then remains for several days to loyally guard them from predators – such as insects, spiders and crabs. Eventually the bright green tadpoles hatch and simply plop into the stream below. Amazingly, the presence of a predator can actually trigger the early hatching of the tadpoles, as a clever escape mechanism.
The Tobago Stream Frog isn’t the only frog endemic to the island; two other Main Ridge frogs that are found nowhere else in the world are the Charlotteville Litter Frog and Turpin’s Litter Frog. ‘Litter’ frogs are so-called for their preference for leaf-litter along the sides of streams, not because of a preference for garbage, although in some places they are forced to put up with plastic trash left by those who pass to collect water from the reserve’s clean supply.
The Tobago Glass Frog in particular has extremely specific habitat needs and tends to be found in small, isolated populations – which means that the removal of streamside vegetation for agriculture or development could wipe out a population overnight. For this reason it is classified as a ‘vulnerable’ species by the International Union for Conservation of Nature.
We must learn more about our native frogs and ensure their survival – especially those that we have sole responsibility for as they are found nowhere else on the planet. If we don’t – who will?