Hedges and Thomas went to the remote Isla Beata specifically with the goal of discovering previously unknown species that might be living there. "We tend to explore more rugged and hard-to-reach areas than other scientists," Hedges says.
The "smallest" and "largest" species of animals tend to be found on islands, the researchers say, because species can evolve there over time to fill ecological niches in the habitat left vacant by other organisms that never reached the remote locations. If a species of spider is missing from an island, for example, the lizards there might evolve into a very small species to "fill" the missing spider's ecological niche.
"Habitat destruction is the major threat to biodiversity throughout the world," says Hedges, who has studied Caribbean species for many years, and has long recognized it as a "hot spot" of threats to biodiversity. "The Caribbean is now widely recognized by conservationists and biologists as an ecological hot spot because it clearly is an area that has an unusually high percentage of endangered species that occur nowhere else in the world," Hedges says. "Most land species on Earth have evolved to live in forested regions, and now humans are destroying the forests--which is a big problem, especially on islands, where species have restricted ranges."
"It is hard to say whether this lizard is as small as a lizard can get, but you would think it probably is approaching that limit because it is the smallest of all 23,000 known species of reptiles, birds, and mammals," Hedges says. "The smaller an an
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Contact: Barbara K. Kennedy
science@psu.edu
814-863-4682
Penn State
3-Dec-2001