Chip of the spider.

• Author: Hardman, Chris
• Position: !Ojo!

TWO RESEARCHERS have come up with a novel way of documenting the impact of land use in Belize by using an overlooked, yet fascinating animal--the tarantula. Steven B. Reichling, curator of reptiles at the Memphis Zoo, and veterinarian Chris Tabaka are four years into a twenty-year study of tarantula behavior in the Lamanai Archaeological Reserve in northern Belize. By using radio tags, they are tracking seventy-five individuals in old-growth forest sites and in areas cleared for cattle or farmland.

When Reichling first went to Belize in 1994, he planned to study ecology and behavior of tarantulas. But over the years his study sites were destroyed as more and more land was cleared for farms or pasture. Like other Central American countries, Belize is abandoning traditional slash-and-burn farming techniques--cultivating small plots of land for a few years and then letting them rest and recover--for the more modern practice of creating large clearings that are left fallow only briefly or not at all. In large-scale agriculture, the land is used consistently without a recovery period, and once the soil yields no more nutrients, the farm is converted to cattle pasture.

Reichling decided to use the tarantula to show how this change in land use affects the environment. Spiders are excellent bio-indicators because they are long lived--up to twenty years--and they stay in one place. "If you've got twenty tarantulas tagged in a milpa in Belize, you will be able to find them within a stone's throw of where they were last time," Reichling says. "More often than not, you'll find them in the same hole." Once a tarantula has established a burrow, it will live there for the next two to ten years. Because tarantulas are so sedentary, they are easy to find. During the day they rest inside their silk-lined home, and at night they wait at the entrance to their home for a meal to come by.

The challenge Reichling and Tabaka faced was how to make sure that the spider in a particular burrow was the same one they had seen before. External marking systems--like the identification tags used on mammals and birds--would not last on an animal that...