Two interesting books on birds have appeared recently. One, Songbird Journeys, by Miyoko Chu, gives a detailed account in the lives of migratory birds and their challenges. The chapter on "Flight Across the Gulf" illustrates the particularly perilous 600-mile journey that millions of migrants make across the Gulf of Mexico rather than following the equally perilous land route. Even hummingbirds are known to make that crossing!
Although Pacific Flyway migrants aren't faced with the gulf dilemma, the strenuous effort does take its toll. The author, who made her mark in integrative biology with a study on "the enigmatic migratory behavior of the phainopepla," states that many songbirds live for less than two years, with more than 85% of annual mortality occurring during migration. Several million succumb to radio towers, windmills, and other high structures.
Most migrants fly at night, sometimes as high as 12,000 feet, directed by those mysterious senses we have only recently begun to understand better. During the day they try to feed and renew their inner capacities. Every fall I notice the arrival of warblers that suddenly appear in the morning along the Feather River, evidently having flown at night, and they seem ravished for food. On the same note, I have seen masses of swallows gather on an autumnal evening to possibly prepare for flying all night. Cliff swallows travel from the Yukon to South America and back each year, a journey of 12,000 miles, and some, like Arctic terns, fly even farther. They must like to fly with wings! Or do they have any choice?
Stated is "Of 10,000 species of birds on earth, 4,600 are songbirds." I wonder if that number is a generalization? My "Birds of America," Golden Guide, 1966, says 8,600 species in the world. "Wildlife Fact Finder" says 9,000. Have I missed something in new discoveries? Experts say there's about one million insect species on earth, but perhaps 10 million undiscovered. The same with fungi; an estimated 60,000 species have been described but maybe 1.5 million undiscovered. Do we really know any absolute facts about earth?
The other book, "Return to Wild America," largely involves a retracing by author Scott Weidensauyl of Roger Tory Peterson and James Fischer's 30,000-mile bird and wildlife survey around the margins of North America they made in 1953. Environmental revelation was just beginning that year when the Supreme Court denied construction of a highway along the historic Chesapeake Canal that was a major bird habitat refuge.
Peterson had added to the zeal of birders in America with the publication of his first field guide in 1934, an effort that was rejected by three publishing houses until Houghton Mifflin printed just 2000 copies. The book sold out in a week, and over the past 70 years has sold over seven million copies...and still going strong in spite of Sibley!
Rachael Carson added to the bird consciousness of the nation with her book, Silent Spring, in 1962, and Earth Day started in 1970 followed by the Environmental Protection Agency and Endangered Species Acts, legislation the industrial age promoters have continued to condemn. Overuse of natural resources is a continual threat to the wildlife integrity of the country, as the author noted in his early 2000 follow-up journey. John Muir said "The battle for conservation will go on endlessly. It is part of the universal warfare between right and wrong." Watch!