Jack Jeffrey stands on a ridge, his gray hair lofting in the breeze, looking down into the changing forest of Hakalau. He's telling a story about Rose Atoll, a pair of small islands in American Samoa that make up the southernmost of the U.S. national wildlife refuges.
"Rose Atoll had pisonia forest, like a lot of Pacific islands do, and the trees had grown real big, but there was no understory at all. It looked as if a great herd of sheep had come through. Everyone assumed that was just the natural state of a pisonia forest. Then they went in and wiped out the rats. Lo and behold, the next time they went back there, the understory plants were growing up strong."
The quiet nibbling of rats can take a radical toll on native plant communities, just like the loud trampling and munching of a herd of sheep or cattle. Jeffrey ponders how the forests of Hakalau might change if the rats were gone. The carefully tended koa seedlings might grow faster, and some of the rare shrubs and flowers might return. A few hahas, with their succulent leaves and bell-shaped flowers, appeared in Hakalau 10 years back, but rats grazed on them so heavily that many of the plants died before they were able to set fruit.
"We were hoping to start using aerial drops of rodenticide here in Hakalau in the next few years, but now it looks like it may take longer," Jeffrey says. "With some of our species on the brink of extinction, the loss of that tool may be a major setback."
"Airdrops of rat bait should be used only in fenced, pig-free areas," he concludes. "It's a reasonable precaution, and it makes sense in terms of conservation. Why control rats in an area where the habitat is continually being degraded by pigs? We need to have areas where we do all the conservation management, and other areas that are managed for hunting. That's the only way it's going to work."
As he walks through the woods, Jeffrey points out a female akepa moving like a brown blur, foraging twice as fast as her flashy mate in a rush to return to her nest; he locates the fork in the trunk of an ohia tree where an aki mother managed to raise two healthy chicks in a single season -- the first time this had been seen in the refuge's history. He is a realist about people and politics, but even the most pragmatic biologist on these islands has to dream. Sometimes, in the shade of the ohias, a man can almost glimpse a long-vanished giant duck waddling at the edge of his vision. And other days, it's possible to imagine a reborn forest of the future, where an aki can live out its life safe from rats.