Saturday, December 4, 2010

Balancing Nature and Research: Why a hurricane may have devastating effects on a spider monkey (Ateles geoffroyi) population in Belize

The small circular valley. Everything brown is destroyed forest.
 It is hot and muggy, I have been hiking for 5 hours over fallen trees and through mangled jungle. I am climbing one of the steepest hills in the home range of our study group of spider monkeys. This is the one refuge of hope as over this hill, there is a small circular valley surrounded by huge hills, which may have protected the forest. As I climb over the ridge I am awe-stricken. On one side of the valley where large lush trees once stood and where spider monkeys used to play, sleep and forage, the hillside is practically bare. Not one tree is left standing. As the sun beats down, I start to wonder what this means. I had spent 14 months of my life researching these monkeys, and now all of it might come to an end. In the distance I hear the faint sound of a spider-monkey whinny vocalization, which gives me hope that some of them have survived.

The path of Hurricane Richard (in red). RCNR is highlighted in yellow.
On October 24th, 2010 Central Belize was hit by hurricane Richard.  This particular hurricane caught many Belizeans off gaurd as the weather reports had slated it to be a Category 1, which would reduce to a tropical storm upon landfall.  Instead the storm increased speed once it hit land leading to wind speeds over 90km/h. Within 24 hours I was on a plane to check out the damage to our research site at Runaway Creek Nature Reserve (RCNR) and find all of the monkeys.  This is not the first time nature has interfered with our research. In 2001 our black-howler monkey (Alouatta pigra) site in Monkey River was hit by a category 4 hurricane which completely destroyed the forest.  
Luckily due to protection from high karst limestone ridges, some of the forest at RCNR was protected. However, an estimated 40% of the original home range of the spider monkeys was completely destroyed.

Sub-adult female spider monkey.
Black-handed spider monkeys (A. geoffroyi yucatanensis) are found in Mexico, Guatemala and Belize and have recently been identified by the IUCN red list as endangered (http://bit.ly/ifAhwB). As ripe-fruit specialists, spiders are extremely sensitive to habitat disturbance. They are typically the first species to disappear from an area and the last to recover.  As a result, this extreme sudden natural habitat disturbance could potentially cause a severe decline in the Belizean population. Both Peccary Hills National Park and the Manatee Forest Reserve were hit much harder by the hurricane than RCNR. These areas probably house almost 30% of the population of spider monkeys in Belize, not to mention the countless other endangered species of mammals and birds that will be affected. 

This area used to be completely enclosed by canopy.
Although this may seem devastating, I do have some hope for the spider monkeys. Atelines in general tend to show a great degree of flexibility in their behavior, diet and social structure. As a result, it is possible these monkeys will be able to adapt to these extreme environmental changes.  As well, part of the forest was preserved, meaning that there will be some fruit available and they won't have to fully rely on leaves.  Finally, Belize is almost like a magnet for hurricanes, so at some point in the past these areas have been affected and the monkeys are still present.  Even if we do see a decline in the population, it is possible that as the forest recovers, so will they.  Only time will tell.

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