Caribbean birds at risk

By Leo Douglas, Contributor

ONLY 12 of the estimated 28 species of parrots present when Columbus arrived remain in the Caribbean today. Of these, no less than eight are currently at risk of extinction.

The Caribbean islands have been accredited with the highest rate of animal extinction in post-Columbian times and most of the extinctions are species of birds. Extinction has relegated some of the Caribbean's unique treasures to pictures in books or specimens lying cold in the drawers of museums around the world.

While extinction is a natural process, within the last 250 years the global rate of extinction has increased by 40 times its expected rate.

Yet in Jamaica, we are still relatively fortunate as our island has 47 endemic species and sub-species, the highest number in the region, most of which are not as yet considered threatened.

But why are so many species threatened? Habitat loss and environmental degradation are the major factors. The earth has never witnessed such massive conversions of natural areas to other land uses. Deforestation, commercial logging, subsistence farming, plantations, arable farming, urbanisation, mining and industry continue to refashion the earth.

The problem is expected to become more acute as the global population is predicted to double within 40 years, creating the need for houses, jobs, food and social and recreational facilities.

Forest loss

As forests are chopped down, the wildlife within them have nowhere to run, nowhere to fly and nowhere to hide. On the islands of the Caribbean almost all of the original vegetation has been eliminated.

In the result of a controversial international survey, the World Resources Institute noted that Jamaica had the highest rate of forest loss worldwide. While the accuracy of the report has been questioned by local interests, the most recent assessment of forest cover completed in 1998 by Jamaica's Forest Department is no more comforting. It found that only eight per cent of the island's forest was minimally impacted by humans, mainly because those areas are too rugged, dry, or wet for agriculture and other human activities.

The International Union on the Conservation of Nature (IUCN) warns that the threat of introduced alien invasive species is as important as the degradation of habitats. This is even more true of the fauna of small islands such as our own which developed in the absence of predatory animals and therefore have no experience or natural defences.

Negative impact

The impact of alien invasive species (in particular introduced predators) also has an adverse effect on local species. Take the example of the Indian mongoose introduced into Jamaica in 1872 to control mice and rats that overran the sugar-cane plantations. It soon became apparent, however, that its introduction was ill-conceived because of the mongoose's fondness for poultry, game and other useful wild creatures.

The last mention of a previously common Jamaican endemic ground nesting seabird, the Jamaica Petrel (or Blue Mountain Duck), was in 1891 when mongoose were found in its empty nesting borrows.

The newest threat to the birds of Jamaica has come from an invasive bird species, the Shiny Cowbird which is a brood parasite. This species does not build its own nest. The female lays her eggs in the nests of other species to be hatched and raised by unsuspecting foster parents as their own. The young Shiny Cowbird cleverly destroys the eggs and young of its foster parent by pushing them out of the nest to fall to their deaths.

And as if this were not enough, our birds continue to be poisoned by the misuse of agricultural pesticides, killed for sport, illegally hunted and eaten or sold.

At the top of Jamaica's endangered bird species sit:

1. The Jamaican Blackbird (not to be confused with other common Jamaican species which are also black) because of the destruction of mature montane and wet forests where it forages in wild pines.

2. The Ring-tailed Pigeon because of illegal hunting and habitat loss.

3. The Golden Swallow. The reason for its decline is unclear but it's presumed to be related to habitat destruction.

Leo Douglas is studying for a Masters Degree in the Department of Life Sciences of the University of the West Indies. He's also the media representative for BirdLife Jamaica.

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