Bird Extinctions Caused By Humans, Fossil Study

Bird extinctions on the island of Hispaniola were caused by humans, but they didn’t happen all at once and many of them weren’t caused by the natives who arrived about 6,000 years ago. That’s the conclusion of a new University of Florida study of almost 5,000 bird fossils found in a mountain cave in southeast Haiti at an elevation of around 6,000 feet. The new look at Haiti’s bird fossils was published earlier this month in journal The Holocene.

David Steadman, the lead author of the study, said that when humans arrived on the scene, they did indeed wipe out some huge charismatic animals such as ground sloths, monkeys, giant owls, and eagles.

However, many of the smaller bird species whose extinctions were blamed on the natives actually managed to hang on until the arrival of European and African immigrants starting in 1492.

For example, the bones revealed a previously unknown species of woodcock that became extinct somewhere between 1350 and 1800 — almost certainly as a result of the colonialists. There were a total of 23 bird species found in the cave, including the Zenaida dove, black swift, and least paraque. The mix of fossils, which includes lizards, snakes, and rodents, as well as birds, suggested to the researchers that the bones are from prey animals brought to the cave by owls.

The Zenaida dove, a relative of the familiar mourning dove, is widespread on Caribbean islands and may actually be increasing as humans open up more cleared habitat.

By contrast, the secretive and nocturnal Least Paraque is rated as “near threatened” and appears to be quietly vanishing because of habitat loss due to land clearance.

An estimated 98 percent of Haiti’s forest has already been cleared for fuel and for agriculture. That isn’t just bad for forest birds. It has been disastrous for the people, who are subjected to repeated landslides and flooding because the mountainsides no longer have trees to break tropical storm force or higher winds that occur each year during the Atlantic hurricane season.

A devastating earthquake in 2010 added to the misery, killing 300,000 people.

The new bird extinction study sheds yet another spotlight on the problems caused by losing the forests in Haiti.

[Zenaida Dove photo courtesy D. Gordon E. Robertson and Wikipedia Commons]