Reviving Extinct Animals: a Tool for Fighting Global Warming?
When National Geographic magazine came out with their cover story on de-extinction in April 2013, it set off quite a controversy. Now that we are on the scientific brink of being able to bring back long-gone species, proponents and critics are...
When National Geographic magazine came out with their cover story on de-extinction in April 2013, it set off quite a controversy. Now that we are on the scientific brink of being able to bring back long-gone species, proponents and critics are hotly debating whether we should.
An intriguing side issue to this discussion relates to our native landscapes and the biodiversity they provide — and how quickly we’re losing them. We know that extirpated animals performed vital services in their ecosystems, which benefit when they return.
Could de-extinction, then, achieve a similar result?
The wolves of Yellowstone National Park
Landscape restoration is defined as the attempt to reverse human impact by returning an ecosystem or habitat to an earlier state; or as some call it, its “predisturbance situation.” Restoration means trying to copy a specific historical structure; in a sense, turning back the environmental clock. Some say restoration is more aptly characterized as making the environmental clock tick again. Standard examples of such efforts include eliminating nonnative, invasive animal or plant species and reintroducing formerly native species.
The wolves of Yellowstone are probably one of the most well-known examples of reintroducing a native species. During the wolves’ seventy-year absence from the park as a result of being killed off by humans, elk were free to roam, reproduce, and feed on the region’s small aspen shoots. Starting in 1995 when the wolves were reintroduced, the elk’s fear and reduced population improved the aspens’ — a tree species in decline all over the West — chances for survival. From the 1920s to the early 1990s, when wolf packs were absent in Yellowstone, no new aspen trees that hadn’t suffered from animal browsing were found. The first time that significant aspen growth was documented was after the wolves came back. In the past few decades, a large number of aspen trees have reached heights of more than seven feet, key for long-term survival because it places the crowns high enough to keep them safe from elk.
Aspens aren’t the only landscape beneficiaries of the wolves’ return. In the absence of their predators, elk not only chewed on trees but browsed heavily in the open flats along rivers and wetlands. Without a predator to evade, there was no reason for them to seek thicker cover. Since the Yellowstone wolves have come back, elk spend more time in the safety of dense vegetation or on the move. As a result, riparian areas that had been suppressed by decades of over-browsing are regenerating, improving habitat for species like beavers and songbirds. Beavers, which create wetlands with their dams, have improved water quality in streams by trapping sediment, replenishing groundwater, and cooling water.
According to the Wyoming chapter of the Sierra Club, other species that rely on healthy riparian habitats and benefit from the presence of wolves in Yellowstone National Park include:
amphibians
insects
moose
small mammals (muskrats and other rodents)
songbirds (warblers, wrens, and thrushes)
waterfowl (ducks, geese, trumpeter swans)
Yellowstone cutthroat trout and other native fish
Without a predator to evade, there was no reason for elk to seek thick cover. Beavers have benefited by the wolves’ return; and, in turn, have improved the water quality of streams.
Without a predator to evade, there was no reason for elk to seek thick cover. Beavers have benefited by the wolves’ return; and, in turn, have improved the water quality of streams.
