Extinction – to intervene or not? (Biodiversity ethics part 3)

Canis lupus. Image by Gary Kramer, from the US Fish & Wildlife Service. Image in the public domain.

Canis lupus. Image by Gary Kramer, from the US Fish & Wildlife Service. Image in the public domain.

A friend (h/t Justin) sent me this article a couple of weeks ago – it seems that this summer, the wolves of Isle Royale in Lake Superior did not produce any pups. Not a one. The total wolf population of the island is down to 8 individuals, and since wild wolves avoid mating with close relatives, that means there are no mates available. Some wolves have already shown minor spinal and other deformities.

Now it’s possible to either bring in new wolves to increase the species diversity, or wait until the current population has died off and bring in a whole new population. This method was used very successfully in Yellowstone National Park: wolves had been completely eradicated inside the park due to both free hunting inside the park and a dedicated program of predator slaughter which took the unlikely name of “Animal Damage Control”.

As became obvious, eliminating the wolves (and some other predators) had fairly drastic effects on the park: the elk bred uncontrollably, and overgrazed deciduous woody trees like aspen. Attempts to reduce the numbers of elk managed to stabilise but not improve conditions in the park, while the absence of wolves also meant an increase in other predators such as coyotes, which consequently devastated other populations such as the pronghorn antelope.

As reintroduction of wolves into Yellowstone worked in restoring the natural balance of the park by impacting many species inside and outside the wolves’ own food chain, so introduction of supplementary wolves or reintroduction of a new colony to Isle Royale might work in a similar way: the wolves would reduce the numbers of moose which are currently having a deleterious effect on trees on the island, and thereby on the entire ecosystem.

But the situation is a little more complex than it first appears. Firstly, there’s the argument of whether to introduce a small number of wolves to the current population, or to allow the current population to die out before introducing a completely new population. Both would allow the survival of a wolf population on the island, although the second, since it would require waiting until the current wolves died out completely, would result in greater damage to the ecosystem than immediate intervention.

Secondly, though, there’s the issue of whether to intervene at all. Moose originally crossed to the island in the first decade of the 20th century by swimming, and caused a lot of environmental damage before wolves crossed an ice bridge in the 1940’s and brought the population under control. The last wolf that managed to reach the island, nicknamed “old grey guy” by researchers, arrived in 1997, and it’s thought that he single-handedly prevented, or at least deferred, the extinction of wolves on the island. See this page for more information about the wildlife of Isle Royale.

Ice bridges are now far less frequent, due to climate change, so if the wolves are to survive, it’s likely that humans will have to intervene every couple of decades. And there’s some dispute about that: some believe that it’s better to ‘let nature take its course’, while the scientists currently studying the wolves believe it’s better to intervene in order to maintain a healthy ecosystem on the island, even if it means recurrent interventions.

Humans have already dramatically affected local and global ecosystems by climate change, logging, agriculture, habitat destruction, and a host of other means. We’ve devastated huge tracts of land, polluted air and water, over-grazed and over-fished, killed off entire parts of local food chains from apex predators to soil micro-organisms, and changed the global climate. I think it’s about time we did our part by starting to repair some of the damage we’ve caused.

And maybe soon the Isle Royale will echo with the yips of wolf pups once again.

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One Response to Extinction – to intervene or not? (Biodiversity ethics part 3)

  1. Pingback: Biodiversity month | Biodiversity Revolution

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