TONI AND I ARRIVED April 22, the day before ice-out and just in time for the annual spring songbird and waterfowl migration. Many species of warblers greeted us, as did our usual bird and ground feeder guests: chickadees, purple finches and goldfinches, chipping sparrows, rose-breasted grosbeaks, downy woodpeckers, juncoes, Harris' and white-crowned sparrows, red- and white-breasted nuthatches, Baltimore orioles, American redstarts, scarlet tanagers, and more. Mindful as we are of studies indicating declines in songbird numbers, it was reassuring to have so many of our friends pay us a visit.

   NOT SO IN THE CASE of waterfowl. We are accustomed to seeing large numbers of migrators, rafting out in the middle of the lake as they rest before moving on. We saw none of that this year. No scaup, no bufflehead, and only a smattering of species that may or may not stick around to nest: goldeneye, wood ducks, mallards. The merganser family, on the other hand, appears to be secure. We did have a pair of hooded mergansers take up residence in one of our nesting boxes. Whether they tough it out remains to be seen.

   FOR MANY YEARS, Toni and I have been tracking the spring appearance at Ten Mile of the ruby-throated hummingbird. Almost always, a male will visit our feeder on May 10. I say "almost" because on occasion the sighting will be May 9 or 11, never before or after. This year we had to be in the Cities May 10, but Gail Becher reported the long-distance flier showed up right on schedule. We returned to the lake May 14, and sure enough, a hummer was at our feeder the next morning. In a few days, the females appeared, courting began, and the summer nesting ritual was under way.

   ALTHOUGH THE RUBY-THROATED hummingbird is typical of our area, there are 320 known species, 16 native to the U.S. and all found only in the Americas. Hummingbirds are well-known by birders for their feisty behavior. In fact, one biologist/ornithologist is purported to have said: ". . . if hummingbirds were the size of hawks, we'd all run around in fear of our lives."

   WE ALL KNOW THAT bird watching is an immensely popular pastime. How dedicated to this pursuit can bird watchers be? The rare appearance of a stripe-headed tanager in Florida this January offers a case in point. The tanager was spotted on Friday. On Sunday, about 95 people arrived at the park hoping for a glimpse. A Pittsburgh man heard about it and was on a jet the next day, saw the bird, and flew back home. A Tampa man drove down, returned home after failing to see it, then came back down after he heard the bird was still there. A woman left her winter home in Okeechobee to add the tanager to her lifelong list of 755 bird species. And so it went. The Florida news came my way from Fran Brandt, a Ten Mile neighbor who winters on the Keys.

   MOTHER EARTH HAS BEEN and will continue to be hostess to an unending procession of disasters, natural and man-made. In modern times the Chernobyl melt-down, the Mt. St. Helens and other volcanic eruptions, plus any number of horrific earthquakes, hurricanes, tornadoes, and floods come to mind. The biggies though, occurred millions of years ago, catastrophes that destroyed large chunks of the earth's life forms. Scientists have identified five extinction events: the Ordovician, 440 million year ago, wiped out two-thirds of all species; the Devonian, 360 million years ago, 50 percent; the Permian-Triassic, 250 million years ago, 90 percent; and the Cretaceous-Tertiary, 65 million years ago, the dinosaurs and 50 percent of all other species. Amazingly, the resilient Earth has always recovered, at least so far. Now, scientists are beginning to talk about the possibility of still another mass extinction, this one man-made (climate change). A number of studies in Great Britain documented sharp declines and even extinctions in some bird, butterfly, and native plant species. According to an article in Science, the findings strengthen the hypothesis shared by many scientists that: "the biological world is approaching the sixth major extinction event in history."

   RESEARCH OUT OF GEORGIA provides convincing evidence that buffer zones composed of trees and native plants effectively remove nitrogen and phosphorous from the soil. The data measured decreases of 60 percent to 65 percent. The study validates recommendations for leaving shore areas as natural as possible, or, where necessary, planting native trees, shrubs, and grasses to create a buffer zone. Any measure that prevents nutrients from seeping into the lake will reduce algae concentrations and improve water quality. Easy to do, attractive, and it works!