By David Gessner

Though it is hard to imagine in this time of bitter cold, our Cape Cod ospreys will be heading north soon, making the 4000-mile trip to our shores and marshes from their winter grounds in South America. Ospreys have now been nesting in my neighborhood here on the Cape for the better part of a decade. My life and work have been firmly rooted in this small patch of earth, but as I watched the birds over the last few summers I often found myself thinking of another place. Long Island, with which we share a glacier-scraped geography, is rarely talked about in positive terms by Cape Codders, who see its overdevelopment as a harbinger of their own future. But it is thanks to Long Island, or at least to specific Long Islanders, that we have ospreys nesting on Cape Cod today.

Several years ago, when I began researching the ospreys' return, I learned the story of an extraordinary man, Dennis Puleston. I learned that Dennis was one of the first to miss the ospreys when they suddenly stopped appearing, and one of the first to understand what was happening to them. In 1948 Dennis began carefully observing and sketching the resident ospreys on Gardiners Island. While growing up in England, he had never seen an osprey in the wild, the birds having been wiped out there, and moving to Long Island after World War II, he looked forward to living close to what he considered a "somewhat mythical bird." Not long after his move he began his studies at Gardiners Island. When he first observed the ospreys, there were hundreds of active nests, but over the years he noticed great changes. "I began keeping records of each nest and its reproductive history. In 1948, an average of more than two chicks fledged from each nest...By 1966, active nests on Gardiners Island had dwindled from over 300 in 1948 to under 50, and in these we could find only four chicks. Ornithologists predicted the end of the osprey as a breeding bird in the Northeast."

Puleston had great respect for Rachel Carson, whom he called "that splendid woman": "Knowing of her work, we collected overdue osprey eggs and took them to the laboratory for analysis by gas chromatography. As we anticipated, residues of DDT were present." Dennis wasn't the first to tie the osprey's decline to the use of pesticides, but it was his careful observations that would help convert this conclusion into political action. The story of what happened next is a familiar one to most of the readers of this publication, but it is a story worth telling quickly again. How Dennis and the other members of the Brookhaven Town Natural Resources Committee objected to the repeated bombing of their island with DDT and how they began to fight against the chemical's use by the Long Island Mosquito Control Commission. How the group finally took the case to court and, for the first time, wed science to law to gain environmental results, finally stopping the spraying and giving birth to what is now known as environmental law. How the group eventually became the Environmental Defense Fund, and how, in 1972, thanks in large part to the groups efforts, DDT use was permanently banned in the United States.

I never knew Dennis Puleston personally and my only connection to him was through his story. But it is a story that has taken deep root in my imagination. Ospreys, of course, were exhibit A during that first trial and it was Dennis who provided the beautiful illustrations of the bird. When I picture him I see him out there on the marshes studying and sketching the ospreys; I picture a man absorbed in the life around him, focusing on something greater than himself. During the years I worked on my osprey book I felt gratitude toward Dennis, not only because the birds were back, but because for me he fulfilled a nearly forgotten role in our society: that of an elder. As I began to spend more and more time out on the marshes watching birds I began to understand that this man I had never met was providing me with glimpses of nothing short of a new way to be. Glimpses of a different, more fulfilling sort of life, a life in unison with a world beyond the human.

These are dark environmental times and it is nice to occasionally have a reason to be hopeful. In the face of the usual litany for pessimism--thinning ozone, depleted resources, acid rain, extinction, the intractable crush of population--it is easy to curl into a kind of mental fetal position, to begin to believe that we are helpless and nothing can be done. While I'm a skeptic by nature, maybe once in a while we need to focus on our victories, not our losses. By looking toward Dennis and the ospreys we can see a little light. We can see what can occur if we are able to exercise restraint. Can see something truly hopeful in the miracle of what we managed not to do.

And now the practical result is undeniable. Thanks to the actions of Dennis and those like him, we have ospreys nesting not just on Long Island but on Cape Cod and throughout New England. Statues and monuments are nice reminders of the dead, but as legacies go, this seems both better and more fitting for Dennis Puleston. How many people can say they impacted the world in such a way? By the time this essay is printed the ospreys will already be on their way back north. I look forward to their return as I do every year. For me the birds exemplify the thrill of a comeback: hope renewed improbably after it had been seemingly, finally, extinguished, the birds filling old ecological nooks they had once disappeared from. This year when I see my first osprey I will think of Dennis Puleston. What better legacy than the resounding of high-pitched cries and the beating of wings?

David Gessner is the author of "Return of the Osprey." He currently teaches environmental writing at Harvard.

(Painting by Dennis Puleston, A Nature Journal, 1992)