Like butterflies? Thank a wolf.
How about wildflowers? Thank a wolf for those, too.
Likewise for the drum of a grouse, the swirl of a bull trout, the trill of a songbird.
Biologist Cristina Eisenberg has spent years studying “trophic cascades” – literally the flow of energy through ecosystems – and along the way has laid bare many surprising strands connecting the web of life.
In March, she joined National Park Conservation Association’s Glacier Field Office on a cross-country ski tour of her favorite scientific laboratory – the North Fork Flathead River Valley, on Glacier National Park’s remote western fringe.
Over the years, Eisenberg has studied the interaction of critters here, paying special attention to top-tier predators such as wolves. Canis lupus was eradicated from these meadows a century ago, then returned in the 1980s traveling south from Canadian wilds.
Turns out, the return of the wolf also has meant the return of enhanced biodiversity.
Without wolves, elk herds ate the brushy bottoms of willow, aspen and dogwood right down to the nub. In fact, tree dating shows that not a single aspen grew to maturity during those wolf-less decades.
No young brush meant far fewer songbirds, both in diversity and in sheer numbers. It also meant no butterfly habitat, and no shady riparian holes for trout. Bull trout eat the bugs that fall off the brush – no brush, no bugs, no bull trout food.
Coyotes moved in, eating the grouse and the ground squirrels alike. Now that wolves have run the coyotes into the fringes, the ground squirrels are again plowing the meadows, increasing soil productivity, planting the seeds for explosions of summer wildflowers.
And those elk, well, they’re still here, alongside muleys and moose and whitetail deer. But today they’re more careful – rather than standing around eating a tree to its roots, they tend to nibble a bit, look over their shoulders, move on, nibble some more.
Species, like national parks, do not – cannot – exist in isolation. They are linked, reliant on sometimes surprising connections to the lands around them. And humans, Eisenberg emphasized, are an important part of that web, too.
“Man did not weave the web of life – he is merely a strand in it. Whatever he does to the web, he does to himself.”
But that’s not Eisenberg. That’s Chief Seattle, in 1854, back when North Fork wolves still outnumbered humans.
It seems modern science and conservation biology are finally catching up.