THIS Christmas season, some 40,000 bird-watching enthusiasts will brave cold early mornings, prowling swamps, meadows, and mountains, to census the birds in their communities. Their daylong bird counts are organized by Audubon's American Birds magazine, which collates the results into a vital picture of America's bird life. Motivated by holiday camaraderie and love of the natural world, these dedicated birders' efforts provide invaluable information on avian population patterns.
But the Christmas bird count and the data generated have a deeper importance. As birders see the effects of pollution and loss of habitat, they have become more sensitive to the interrelatedness of all life; this is why the National Audubon Society has evolved naturally from a birding group to one of the nation's largest and most deeply committed conservation organizations.
This will be the 87th year since conservationist Frank Chapman, editor of Bird Lore (predecessor of American Birds and Audubon Magazine), held the first Christmas bird count as a protest against the grisliness of an earlier custom, the ``side hunt.'' According to Chapman, ``Sportsmen were accustomed to meet on Christmas Day, `choose sides,' and then, as representatives of the two bands resulting, hie them to the fields and woods on the cheerful mission of killing practically everything in fur or feathers that crossed their path.''
Today's bird count represents the most extensive, continuous, geographically comprehensive, and longest-term set of data in American ornithology, with participants from South America to the Arctic Circle. The information collected provides valuable statistics on declines and increases in particular species, geographical shifts in winter ranges, and other indicators of the status of bird populations.
``Side hunts,'' of course, are part of the past. But even more-insidious threats remain. Pesticides, toxic chemicals, and industrial pollution eliminate the food sources upon which many birds depend. Acid rain created similar problems. Many birds are poisoned each year by ingesting the spent lead shot of hunters. And vanishing habitat - whether in tropical rain forests or in the United States' own wetlands - threatens many of our most common birds' wintering and summer nesting grounds.
But the outlook is far from bleak this holiday season. In recent congressional elections, environmental issues played a major role in many states. We now have one of our best opportunities in recent memory to pass meaningful, long-needed legislation. Among the items on environmentalists' Christmas ``wish list'':
A revised and strengthened Clean Water Act, providing for cleanup of nonpoint source pollution, and protection of ecologically fragile bays and estuaries (similar to the bill vetoed by President Reagan in November).
Renewal of the Endangered Species Act. Last year, Congress failed to reach agreement on a new act.
Renewal of the federal pesticide law, which regulates these hazardous substances to protect human safety as well as natural systems.
Legislation to limit the sulfur and nitrogen oxide emissions that cause acid rain.
Environmental safeguards for ground water - the underground aquifers that provide drinking water to one-half the US population and are increasingly endangered by toxic pollutants.
There is much more, of course, that needs to be done if we are to leave behind a global environment in which our children and grandchildren will be able to experience the same diversity of species that we celebrate with the annual bird count.
Such difficult problems as tropical deforestation and global population growth will need to be faced up to. The export of dangerous agricultural and industrial chemicals to third-world nations and the resulting contamination of ground-water supplies must be brought under control. But the opportunity to bring about change is ours.
As we take time out from Audubon's work on these and other issues, we take no small pleasure in knowing that a Christmas bird counter can still have a chance - though a small one - of seeing an ivory gull, a tufted duck, or a fork-tailed flycatcher. One of these would make birders glow with pride over their Christmas lists.
Peter A. A. Berle is president of the National Audubon Society.