West Indian mammal extinctions
The large islands of the Greater Antilles (Cuba, Hispaniola, Jamaica and Puerto Rico) were once home to an endemic evolutionary radiation of monkeys and at least four genera of sloths, including some terrestrial animals (Megalocnus) over 100 kg in body mass and others (Neocnus) that were arboreal and smaller than living sloths. These islands also contained a high diversity of native rodents and insectivores, including ‘giant hutias’, spiny rats, and tiny Caribbean ‘island-shrews’ or nesophontids. Hispaniola, the second largest and geotectonically most complex West Indian island, contained around 25 endemic land mammals before human arrival. Further east, the smaller islands of the Lesser Antillean chain were also home to their own unique mammal species: rice rats that grew as large as cats on islands such as Guadeloupe and Martinique.
However, almost all of this diverse fauna is now extinct. Island faunas have experienced massive-scale extinction events over the past few thousand years and into the modern historical era, and West Indian land mammals have suffered the most severe extinctions of any mammal fauna anywhere in the world during this period. Understanding the reasons why there have been so many mammal extinctions in the Caribbean is a continuing problem. Without a good understanding of when different species died out it is impossible to identify what historical factors were responsible for their disappearance, but accurate dating of subfossil material using conventional methods remains a challenge due to degradation of bone collagen under tropical conditions. However, it has become increasingly clear that most of these extinct mammals survived until the arrival of humans in the Caribbean around 6000 years ago, and a range of human activities – overhunting, habitat destruction, and the introduction of exotic species – are now considered to have driven the Caribbean mammal ‘mass extinction’ event. Further research into these extinct species and their pre-human ecosystems may therefore be able to provide important new insights into the conservation of the few Caribbean mammals that still survive today.
You can download the checklist of the described West Indian mammal extinctions here.