This is a fascinating article about the Rocky Mountain Locust and the species’ demise from Jeffrey Lockwood writing for The High Country News. Click through and read the whole article. Here’s an excerpt:
How early settlers unwittingly drove their nemesis extinct, and what it means for us today
Picture swirling snow as far as the eye can see — in the middle of summer. Now, imagine this blizzard of flakes transforming into a swarm of locusts. This isn’t just any swarm, but the largest congregation of animal life that the human race has ever known. Picture yourself in Plattsmouth, Neb., in the summer of 1875.
A swarm of Rocky Mountain locusts streams overhead for five days, creating a living eclipse of the sun. It is a superorganism composed of 10 billion individuals, devouring as much vegetation as a massive herd of bison — a metabolic wildfire that races across the Great Plains. Before the year is up, a vast region of pioneer agriculture will be decimated and U.S. troops will be mobilized to distribute food, blankets and clothing to devastated farm families.
I came across an account of this staggering swarm in the Second Report of the U.S. Entomological Commission, published in 1880. By clocking the insects’ speed as they streamed overhead, and by telegraphing to surrounding towns, Dr. A.L. Child of the U.S. Signal Corps estimated that the swarm was 1,800 miles long and at least 110 miles wide. This suffocating mass of insects was almost large enough to cover the entire states of Wyoming and Colorado.
Swarms like this — albeit usually on a smaller scale — are part of the life cycle of locusts around the world. At low population densities, these insects behave like typical grasshoppers, to which they are closely related. But when crowded, this insectan Dr. Jekyll transforms into Mr. Hyde. Chemical cues from their feces and frequent disturbance of tiny hairs on their hind legs set off the changes. The changelings aggregate in unruly mobs, feed in preference to mating, grow longer wings and a darkened body, and irrupt into rapacious swarms…
The break in the case [ed. determining why they are extinct now] came during my teaching. In an effort to work some interesting (i.e., nonmathematical) elements into my Insect Population Biology course, I dug into the ecology of the monarch butterfly. Much like the locust, this species distributes itself across the face of the continent. And much like the locust, the monarch is poised on the edge of extinction in North America.
How could a butterfly that fills roadsides and fields from Texas to Maine be in jeopardy? After migrating northward each summer, this species returns to overwinter in the remote mountains of Mexico. Its populations stretch across North America, only to collapse back into a few shrinking pockets of forest. Loosed on these pockets, a logging crew armed with chain saws could put an end to this magnificent butterfly in a matter of weeks.
There was the answer, staring me in the face. Like the monarch butterfly, the Rocky Mountain locust was tremendously vulnerable at certain times in its life. Between outbreaks, the locust hid out in the river valleys of Wyoming and Montana — the same river valleys that settlers had discovered were best suited for farming.
By converting these valleys into farms — diverting streams for irrigation, allowing cattle and sheep to graze in riparian areas, and eliminating beavers and their troublesome dams — the pioneers unknowingly wiped out locust sanctuaries. They destroyed the locust’s equivalent of Mexican forest wintering grounds. They doomed the species.
