Corcovado National Park, December 2005

The Park has reopened to visitors, but the full extent of the damage won’t be clear for quite some time.  Some estimates suggest that half of the endangered spider monkey population died over the past two months.

The park was closed in mid-November amid fears that a viral or bacteriological pathogen was killing the animals and it might be transferred to humans.  Nature lovers were ignoring warnings not to handle wildlife, showing up at biological stations carrying monkeys too weak to move in hopes that the rangers or scientist might be able to save them.

Laboratory tests ruled out disease, and careful observation of the live animals and study of the bodies revealed that the true cause of death was starvation.

Corcovado has been inundated with double the normal amount of rainfall since the beginning of September-twelve feet in all.  By November the region usually begins to dry out, but not this year.  Forty-one inches of precipitation fell in a month when the average is less than half that much.

The extraordinary rains also brought cooler temperatures and the combination affected the fruiting pattern of many tree species.  Some didn’t fruit at all, and others set fruit, but it fell prematurely and rotted on the ground.

Deer, sloths, and birds were all affected, but the monkeys were the hardest hit, and the spider monkeys suffered more than the other three species.  Squirrel and Capuchins supplement their diets with insects, leaves and stems, and howlers eat mostly leaves, but the spider monkeys rely almost exclusively on figs and other fruits.

The question that will be answered over the coming years is whether the fall of `05 was an anomaly or a new standard set by the pattern of global climate change that’s also shown us open water at the North Pole for the first time and spawned hurricane seasons like none before.  If rains like these persist many of the species that find their last best refuge in Corcovado won’t survive more than a few more years.

Update, March 2006

The Wildlife Conservation Society, Conservation International and the Costa Rican government have funded a research project to track and census monkey populations as well as marking trees and inventorying fruit production.

This will provide a better understanding if similar weather patterns occur in the future and help document the effects of the climate changes.  Unfortunately it won’t have any impact reducing the likelihood of future weather induced starvation; that’s up to the populations scattered around the world who are modifying the climate.