What You Can See on March 19

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. Fairy Shrimp Vernal pools -- those pockets of snowmelt and rain that vanish in the heat of summer -- teem with life unseen by those who hasten through their days oblivious to Earth’s wonders. Do not be one of them. You can’t be sure you’ve found a vernal pool unless you identify one of the obligate denizens such as fairy shrimp, an order more ancient than dinosaurs. Keep looking under the dappled surface, between the floating pine needles. First you’ll see the two white stripes on the tail, then a translucent creature roughly an inch long will materialize. Fairy shrimp hang and hover, always swimming on their backs, rowing and breathing with 11 pairs of legs. They are there because fish are not. Ducks eat fairy shrimp but also transport their eggs to other vernal pools. There are two kinds of eggs -- one for times of plenty and one for low, warm water laden with salts concentrated by evaporation. The first type, laid by unfertilized females, quickly produce clones. The second, actually encysted embryos, result from male-female unions and remain viable through summer dust and winter ice. Because vernal pools are generally regarded as worthless puddles, many species of fairy shrimp are endangered. Hard Drinking Woodpeckers East of the Rockies, yellow-bellied sapsuckers are moving north as sap rises in some 250 species of native tree favored by these furtive, medium-sized woodpeckers. Listen for the drumming courtship duets of both sexes and watch for the horizontal lines of squarish holes, all pointed slightly downward so as to collect sap. After a sapsucker has excavated a tree, it will leave to work on another, then return and lick the sap with its brush-like tongue, tilting its head back as if swigging beer. Describing one feeding bird, 19th and early 20th century naturalist John Burroughs wrote: “Then, when the day was warm, and the sap ran freely, he would have a regular sugar-maple debauch, sitting there by his wells hour after hour, and as fast as they became filled, sipping out the sap.” Yellow-bellied sapsuckers guard their holes, squealing angrily at other birds and chasing them away. You can occasionally attract them with suet, peanut butter or even humming bird feeders; and they will nest in bluebird boxes.