The Problem When Once-Endangered Animals Become Too Plentiful
Wildlife biologists and other conservationists often suffer from chronic pessimism—not surprising, given the endlessly gloomy news about habitat loss, species extinction, and the latest delicacy being eaten by rich people in China. (“Boiled baby pangolin, dear?”) But sometimes things go right.
“There are glimmers of light that lead me to feel that what I’m doing is not absolutely mad and idiotic and senseless,” the author and captive breeding proponent Gerald Durrell once remarked. He told me this one morning on the Isle of Jersey while both of us were consuming large glasses of whiskey well before cocktail hour, or even lunch. But we toasted his point because it was a good one: There are success stories, and conservationists should cheer up and celebrate them.
A new article in the journal Trends in Ecology and Evolution makes the same point, minus the whiskey, and also proposes an agenda for dealing with the almost miraculous—but sometimes complicated—transformation of once-endangered species into commonplace neighbors.
Let’s start with a few of the success stories. “In the nineteenth century,” the University of Vermont’s Joe Roman and his coauthors report, “the elephant seal was hunted so intensively in the North Pacific that it was presumed extinct,” and it may have been down to as few as 20 survivors by the 1880s. Today, because of protections implemented in the 1920s, there are 200,000 elephant seals—possibly more than at any time since humans first encountered the species. Likewise, “by the 1960s, American alligators were hunted to near extinction and rarely seen in the wild,” according to Roman. “Today they number in the millions and are a common sight on golf courses and in urban canals.” In the 1970s, brown pelicans, bald eagles, and red-tailed hawks also came back from the brink of oblivion because of the ban on the insecticide DDT, which inadvertently destroyed their eggs. At the moment, in fact, I am sitting on my porch watching one of the hundreds of local osprey, saved from near extinction owing to DDT, flying home to its nest with a fish clutched in its talons like an auxiliary fuel tank.
That sort of thing can make it seem as if the world is being put right again. But to the general public, it can also seem at times that things are going wrong instead. Gray seals, which once lived all along the East Coast, from Canada down to Cape Hatteras, were largely extirpated from their home range in the 20th century. Now, thousands of them lie around on some beaches in Cape Cod and bedevil local fishers. “One of the biggest issues if you grew up on Cape Cod in the last 6o years,” said David Johnston, a Duke University marine biologist and coauthor of the new study, “is that you didn’t see any seals then. Now they’re back, and you have no memory of seals, and maybe your parents have no memory.” So the seals on the beach end up seeming like an invasive species rather than returning natives. Even ospreys can seem like a headache to some—for instance, when there are so many of them that they nest on electric towers and short out the power.
The new article proposes four steps to ease people into the good news of species recovery: “First, when protection works, conservation scientists and nongovernmental organizations should celebrate these success stories, actively engaging the public in recording a species’ return to former ranges and framing the recovery trajectory in light of the historical abundance, ecosystem health, and natural capital.” Without that understanding, people tend to call for culls before they even understand how an animal lives.
The coauthors argue, second, that conservationists should push for down-listing and delisting of species that no longer need protection. That can free up time and resources for other plants and animals that are still in trouble. Third, wildlife biologists need to anticipate and address potential conflicts as a species recovery is occurring. People who make a living from the abalone shellfishery in southeastern Alaska were loudly resentful of “new” competition from returning sea otters. So scientists needed to explain ahead of time that the sea otters also restored the devastated kelp forests, helping other commercial fisheries because the kelp serves as a nursery ground for many species.
Finally, before anybody culls or translocates animals, the coauthors write, researchers need to understand the true costs and benefits of these decisions. A complete analysis can help transform a recovering species “from scapegoat to valued neighbor.”
Though the article doesn’t make the point, the bottom line is that conservation really works. In the 1970s and '80s, the U.S. Congress passed landmark legislation, such as the Endangered Species Act, and signed international treaties, such as the Conventional on International Trade in Endangered Species. The result is that species once irrevocably bound for extinction now routinely fly over my house and probably yours too. Yes, we need to make sure those past measures are being actively enforced—and, yes, we need to make our craven legislatures continue to take bold new actions to protect wildlife.
But now and then we should also set aside the gloom, and the whiskey, and instead raise a glass of champagne to the environmental victories all around us.