‘Near-Complete Extinction’ Threatens Small Rainforest Mammals
Think rainforest and you probably visualise vast tracts of virgin jungle and woodland, unexplored and unchanged by the human race. But sadly, it’s very rarely so. These days you’re more likely to find rainforest ‘fragments’, also called ‘forest islands’, small areas left alone for one reason or another, surrounded by huge areas of ruined forest.
Inhabitants of rainforest ‘islands’ at serious risk
Now it looks as though wildlife living in these small islands of unspoiled forest could be at much greater risk of extinction than anyone had previously anticipated. A study covering twenty years reveals the near-complete extinction of small native mammals in fragments left by the creation of a massive hydroelectric reservoir in the Thai rainforest. The situation is so bad that the survey’s leader, Luke Gibson from the National University of Singapore, called it an “ecological Armageddon”, adding, “Nobody imagined we'd see such catastrophic local extinctions.”
The Science Today journal reported the results, which don’t bode well for other rainforests which face not just deforestation but being broken into smaller and smaller pieces. According to Antony Lynam of the Wildlife Conservation Society, the fate of much of the planet’s remarkable biodiversity will ultimately depend on the research team’s findings.
The study looked at how long species can live in forest fragments whose surroundings have been profoundly affected by human activity. The longer these islands exist, the better idea scientists can get of their health. Biodiversity is a measure of that health, and what the team saw makes depressing reading. It looks like small native mammals disappear with frightening speed, with less than one individual surviving in each island.
Field rats’ field day
As well as human-led deforestation and damage there’s another culprit, the invading Malayan field rat, which has displaced more or less all native small mammals simply through being so successful in its invasion of the surrounding areas and the islands themselves. As Gibson said, “The bottom line is that we must conserve large, intact habitats for nature. That's the only way we can ensure biodiversity will survive.”
Guest article by the Rainforest Foundation.