This task may sound no less daunting than sighting a resplendent quetzal to the average weekend birder. The quiescence of birders is no surprise to such master birders as Mr. Dunne. He directs the Audubon Society's Cape May Bird Observatory at the Jersey Shore, where hotels that used to close after Labor Day are now booked deep into the fall for the seasonal bird migrations. The evidence of birding's popularity is mounting, with two major new field guides vying for the lucrative market, scores of new festivals helping local economies in some of the most exotic birding areas and an increasing variety of pro-bird measures. These include the annual Keep Your Cat Indoors Day on May 12 to sensitize the nation to the loss of millions of backyard birds every year.
Most birders ignore kitsch trappings and make do simply with a pair of binoculars and a field guide.
Birding has grown with Americans' leisure time and disposable income. Conservationists estimate that one in every six species is in decline in North America and could wane by half in the next 30 years as humans use up more land. Mr. Sibley doubts some of the booming numbers but not the passion of modern birding. Mr. Sibley is in daily demand as a speaker now that his book, based on 30 years of experience as a photographer and birder, has become a best seller, with 300,000 copies in print. It is being hailed as on a par with the classic Audubon and Peterson field guides.