Armchair Birding: Where Do Camels Belong? Why Invasive Species Aren’t All Bad, by Ken Thompson
~ Anne Kilgannon
Ken Thompson knows how to grab a reader’s attention with challenging questions, ones you may never have thought of posing before and are startled when he thrusts them into your view. So where do camels come from? I won’t give him away, but it’s not from where you’d expect. He briskly poses several more ways to answer his question: Where did they evolve? Where have they been present for the longest time? Or more recently? Where do they thrive without human assistance? The real question is, what do we mean by “belong?” What does it mean to be an alien or native animal or plant? He’s willing to chase the answer as far back in time as science can take us. What he finds upends many of our usual assumptions. It’s unsettling and provocative but somehow feels urgent and necessary, “What if we’ve got it all wrong?”
I read this book with my recent concerns about owls on my mind. Currently, Barred owls are being weeded out of Northwest forests as ruinous invaders and competitors as part of our effort to save the Northwest Spotted owls, which can be prey for the larger birds. Barred owls have been migrating from their original homelands in the eastern states, crossing the continent helped by human-planted trees and now can be found encroaching on forests here that support the endangered smaller owls. An elaborate plan to eliminate this threat has bird protectors of one owl suiting up with rifles and heading into nighttime forests to rid the area of this new owl. Hundreds, maybe thousands of them. It reminded me of the bygone days when other biologists shot eagles and hawks to save songbirds and domestic chickens even though raptors mainly hunted rodents. Untold numbers of eagles were similarly killed to save salmon in Alaska. Besides predator birds, the English sparrow and starlings were anathema and commonly ruthlessly hunted, although they are both still very much with us. All this carnage… Thompson asks us to step back a moment and examine our methods and our assumptions that give rise to such campaigns. Rat and mouse populations exploded after their main predators were decimated; farm crops were equally devastated. Was our thinking too narrow, too shallow?
For the most part, Thompson relieves us of the contemplation of the bloodshed and mayhem by focusing mainly on plant life: Purple loosestrife, Japanese knotweed, Scotch broom, various thistles and invasive grasses, even dandelions. He also examines the troubling situation with invading zebra mussels, certain insects, brown tree snakes, sea lions and wolves. Do they pose a real danger? Are the measures we are taking to control them effective? He searches through all the relevant journals and scientific studies to discover, frankly, not very much progress on many fronts. For all the studies, it seems that we just don’t know enough, or we are asking the wrong questions, or—and in the end this one really struck me—we should trust the workings of evolution and habitat restoration more. Our time frame has been too restrictive. We seem to panic and grasp at solutions too soon. Or sometimes the solution is staring us in the face: stop the logging of old growth forests and see if there will be room for all the species that rely on them.
One of the most compelling issues Thompson explores is how we think we know what is native to a place and what can be called an invading species. Very basic questions yet seldom explored. He is writing from Britain but likely every place has stories of this kind. Did a plant or animal find a foothold after the last ice age receded? Or when the Romans established themselves? The Norman conquest or more modern times when adventurers scoured the globe for exotic trees and flowers for their gardens, some of which brought with them insects, diseases, and other afflictions? The ballasts of ships engaged in international trade can swarm with other cargo. Has it always been thus? Where do we draw the line? If an introduced species “naturalizes” does it ever belong? Thompson advises a more wait-and-see attitude. Has the newcomer added to our biodiversity? Increased our resilience to climate change? In fact, is the newcomer a climate migrant or refugee? Can we adapt and make room for change? Change is coming nonetheless. Do we really know enough to play thumbs up or down? Climate change upends so many of our assumptions. Sometimes when I see starlings massing in the sky, I try to see the beauty in their amazingly coordinated swirling and not think about my despair when I see one poking into the area in which I know the local hummingbirds have secluded themselves. But what if the starlings were the last birds to survive us? I am not a biologist, I don’t know how to evaluate Thompson’s thesis. But I’m intrigued by many of his questions, his debunking, his challenges to assumptions that maybe fit in their day but now face new circumstances. Something to ponder and discuss.
