What You Can See on March 14

From Audubon’s Earth Almanac by Ted Williams and compiled in “Wild Moments,” edited by Connie Isbell, Illustrations by John Burgoyne, Storey Publishing, 174 pages. Birding by Ear Great billows of warblers are now rustling through eastern hardwood forests -- quick, gaudy birds representing some 50 species. From South and Central America they follow the green, insect-rich edge of spring, wafting across the Yucatan Peninsula to the Gulf Coast, blowing up the Mississippi, the Appalachians and the Atlantic seaboard. Forget trying to identify them all visually. They move too fast and feed too high. You'll have better luck learning their distinctive songs from tapes produced by the Cornell Laboratory of Ornithology. (Call: 607-266-7425.) After a southwest wind watch the weather channel for localized rainstorms which can force down night migrants, instantly filling bare woodlands with caroling and color. Get there before first light because some of the unusual warblers may sing only for the first hour. Sky Flakes Robert Frost called them "sky flakes" and "flowers that fly and all but sing." When the last corn snow is a puddle on the greening earth they start emerging from overwintering pupae to skip through woodlands, fields, prairies and backyards from Pacific to Atlantic and Gulf to tundra's edge. They are azures -- quarter-sized butterflies, usually dusted with cobalt scales. Most field guides have the taxonomy wrong; lepidopterists have recently discovered that what they had been calling the "spring azure" may be at least half a dozen species. There is indeed a spring azure -- one of our earliest emerging butterflies, whose flight period wanes in early May and whose pupae go directly into diapause until the following spring. Then there is the slightly duller summer azure which in most of its range starts flying in June and which produces up to three generations before its last flight in autumn. This is the one you're likely to see in treeless areas and city parks. Among other recently discovered species are the cherry-gall azure, the coastal holly azure, and the hops azure. If you see a diminutive blue butterfly between the flight periods of spring and summer azures, catch it. You may have a new species.