National Geographic : 1964 Jun
while holding up large squares of colored cloth or cardboard. "Any flat surface moving toward them seems to make them panic," he reported, "especially red surfaces." But once the panic was over, the birds were back. Next Dr. Frings tried a grid of electrically charged wires, ten feet apart and six inches off the ground. He found that no birds would nest in that grid, even after the electricity was turned off. But the grid was judged to be Will mortars rout gooneys? Helmeted sailors pre] fire smoke bombs against a large concentration. WI smoke blew away, the birds still held their ground Red smoke rolls from a hand-placed bomb amonl of black gooneys. The billowing stream turned some red but caused no visible signs of annoyance. The 846 retired from the field. more hazardous to humans than to the birds. We tried two more noise-making schemes. First, carbide exploders. These are metal cans containing lumps of calcium carbide on which water drips, to produce a highly explosive gas. Every few minutes, automatically, a spark ignited the gas. The noise was like can non, and it bothered lots of people on Mid way. The gooneys just shook their heads. And then there were taped distress calls, which received much attention from Dr. Frings. He had recorded sounds of birds in trouble and discovered that by playing his recordings he could scare away other birds of the same species. This technique had of ten worked with starlings. But the recordings to date have proved only mildly disturbing to Midway's black gooneys. To white gooneys, not at all. Birds Forget How to Land But we were not discouraged. We felt sure that continued banding and surveillance of gooneys would reveal the facts needed to control them. We do not yet know at what age our two species begin to breed, but evidence points to seven years, more or less. Parents spend nine months of pare to the year incubating their single egg ien the and rearing their offspring. They spend the other three months at sea, gliding close to waves and occasion ally alighting on the water as ducks Snests do. They range the North Pacific chicks From America to Asia and north into troops the Bering Sea, catching fish and squid, and sometimes following ships for refuse (map, page 844). The gooneys start coming back to Midway late in October. This is a great event for the people on the is land. After several months at sea, the birds apparently cannot remember how to alight on land. They have to learn all over again, the hard way. In they glide from the blue Pacific, over the line of breakers on the bar rier reef. Across the pale-green lagoon Sand the brush-covered dunes they S come, along the beach, down the main street of the residential section. Each heads unerringly toward the spot it has used for years for nesting. We have recaptured several of the first birds banded on nests near for mer Gooneyville Lodge-still laying eggs on the same site 26 years later.