Tracking the Devastation Caused by a Thriving Species
This is no ordinary field work: To prepare for their three-month stint in the arctic tundra near Hudson Bay, students from GSUC's Ph.D. Program in Biology must take survival courses. And though their barracks is protected by an electrified fence, they are trained to use firearms loaded with firecracker-like "scare cartridges" to keep bears at bay.
This hardy team of research scientists--a group of about eight has studied the area from May through August each year since 1981--is led by Robert Rockwell of the GSUC Ph.D. Program in Biology, The City College, and the Ornithology Department of the American Museum of Natural History in New York.
A native of southern Ohio who grew up hunting and fishing, Rockwell earned his bachelor's and master's degrees at Wright State University and Ph.D. at Queen's University in Kingston, Ontario. He began studying the Hudson Bay area in 1969, when he was a student himself.
Rockwell's first view was of a harsh but balanced environment where the grasses grew, the beautiful blue and white snow geese nested and hatched their goslings and ate the grasses. But today, when Rockwell and his GSUC students go to the area, it is to monitor the devastation of that delicate tundra environment by the recent exponential increase in the snow goose population.
"What used to look like a nicely mowed lawn was suddenly pockmarked," Rockwell says. "Instead of eating the grasses and letting them grow back, the geese were ripping them out by the roots. Clearly there were too many geese and not enough food. The goose population was growing at a staggering rate of 5 percent or more a year; a healthy rate is 1 or 2 percent a year. So where in 1972 there were about 1.5 million geese, today there are 10 million.
"In the tundra, which is frozen solid eight months of the year," he continues, "it takes 15 to 20 years for torn-up grass to come back. And without the grass, water evaporates, the salinity of the soil increases, and then everything dies. We were observing more pockmarks than grass. So we asked, what's causing this? Why are there so many geese?"
The answer lay down south, where the snow goose's winter habitat was being destroyed. In a most unusual case from the annals of conservation, the snow goose had not only adapted to this destruction--it had actually flourished and multiplied. Rockwell, working in the bird's spring and summer habitat up north, was observing the downside to this seeming success story.
"Since the 40s," Rockwell says, "people had been draining and developing the land in the Texas
and Louisiana coastal marshes of the Gulf of Mexico that had been the bird's traditional habitat.
"You might think that would result in fewer geese," he continues. "But these critters aren't stupid. About 200 miles north of the Gulf Coast, farmers had been planting rice since the 40s; it remains a huge cash crop in Louisiana, Texas, Arkansas, eastern Oklahoma. The geese, which will eat any kind of plant, found they liked rice even more than the spartina they used to eat; then just a bit further north they found soybean fields and rapeseed and millet and corn.
"So the snow goose's winter habitat, which had once been a half-mile-wide stretch from southern Texas to 100 miles west of New Orleans," he says, "now included essentially the entire heartland of the United States. The new environment was so rich that the birds' natural survival rate of 70 percent shot up to 90 percent.
"That tells you why there are so many geese," Rockwell adds. But there is a more difficult question: How can the number of geese be reduced, and the natural balance restored, before the system collapses? Rockwell is among the many conservationists who believe that easing restrictions on hunting the snow goose might help resolve the matter. And he is working to bring the area's plight and its implications to the attention of people who can help.
One dramatic example is Rockwell's address two years ago to a group of senior officials from the Canadian Wildlife Service and the U.S. Fish and Wildlife Service at a research facility near a Delaware National Wildlife refuge.
As he began his lecture, he says, "Suddenly, a huge flock of snow geese flew over the building honking. You could not hear me for the din; I had to shut up. When they had passed over I said, 'That's what three-quarters of a million geese sound like. We're dealing with 10 million.' "
Afterward, Rockwell remembers, Paul Schmidt, the Director of the Office of Migratory Bird Management in Washington, D.C., said, "I've heard of audiovisual presentations, but I think you have outdone yourselves."
"I staged it, I admit it," Rockwell says. "Of course we knew when the geese would be crossing over from the water, where they spent the night, to feed in the cornfields across the highway. But we made our point."
