The Big Bad Wolf?

Wolves were eradicated from Colorado about 80 years ago, but on November 3rd Colorado voters will have the opportunity to re-evaluate that situation when they vote on Proposition 114, the Gray Wolf Reintroduction Initiative (2020).

Opponents of the measure believe forced reintroduction will create conflicts with the state’s growing population and will threaten pets and livestock.  Additionally, according to Colorado Public Radio, a significant number of conservationists, outdoor enthusiasts, hunters, farmers, ranchers, and wildlife management professionals have formed a coalition to oppose the measure.

Among other factors, they argue reintroduction will have devastating effects on native elk, moose, and deer populations while spreading Gray Wolf disease/hydatid disease among humans, pets, wildlife, and livestock.  Meanwhile, Proponents counter with stories of successful reintroduction elsewhere in the U.S. as well as the numerous ecological benefits.

To be clear, there are legitimate arguments on both sides of the issue, but the one I keep falling back on is the ecological phenomenon known as “Trophic Cascade.”  And while there’s a great You Tube video on the subject, I’ll give you the Cliff’s Notes version here.

Trophic cascade can best be described as an ecological phenomenon triggered by the addition or removal of to predators involving reciprocal changes in the relative populations of predator and prey though a food chain, which often results in dramatic changes in ecosystems structure and nutrient cycling.  Additionally, it is a very powerful indirect interaction that can control entire ecosystems and occur when predators limit the density and/or behavior of their prey, which enhances the survival of the next lower trophic level.

But that’s just the scientific explanation; so I thought we might look at the matter from a layman’s perspective.

At the time the wolves were reintroduced deer and elk were overrunning the park, and this over-abundance of ungulates caused over-grazing in much of the park; as a result, vegetation began disappearing.  But shortly after the wolves were reintroduced amazing things began to happen.  These apex predators started to thin the deer and elk herds, that as a matter of survival, began avoiding the valleys and gorges where they could be most easily trapped and killed.  Before long these formerly abandoned areas began to rejuvenate, and in many areas around the park the number of trees quintupled; and by the early 2000s spaces that had been barren for decades began to grow willow and aspen forests.

As the forests spread, the park began to see increasing numbers of both migratory and songbirds.  Another positive consequence of the spreading forest was that the beaver population increased, and these semi-aquatic rodents not only ate the new trees but also began harvesting them for dams.  Beavers are nature’s true engineers and the dams they built created habitat for muskrat, otters, ducks, fish, reptiles and other amphibians.

The wolves also killed coyotes, which meant the rabbit and vole populations increased creating food sources for hawks, weasels, foxes and badgers.  Additionally, bears, eagles and ravens began eating the carrion from the wolf pack kills.  Interestingly too, the bear population further benefitted due to the nutrient-rich berries on the park’s regenerated shrubs.

The regenerating forests also meant less erosion, which stabilized the banks of the rivers & streams allowing them to become more fixed in their course resulting in permanent pools of water that created even more habitat for wildlife.  In essence, the reintroduction of wolves changed not just the eco system but also the physical geography of Yellowstone.

I have only ever seen one wolf in the wild and that was from about 30 yards away; I watched as it ran up a mountain slope with incredible ease and grace.  And in a word, the animal was magnificent!  So, will the reintroduction of wolves benefit Colorado as it did Yellowstone?  We can only speculate.  And while there are two sides to this issue, I must admit that the benefits of trophic cascade make for a very compelling narrative.

Quote of the day: “Wolves and people were not natural enemies. The humans’ relationship with other animals established their rivalry with wolves.”—Jon T. Coleman