Yet, I wonder, might not older, quieter methods, such as track and scat data, be more appropriate in wilderness areas? Biologists studying bighorn sheep in the Grand Canyon found noticeable changes in feeding patterns and movement patterns in the presence of helicopters. The animals spent 14 percent less time feeding during the spring and 42 percent less time feeding in the winter, all the while traveling 50 percent farther while doing so.

Gordon Hempton, John Grossmann, One Square Inch of Silence-…, loc. 485