Fishery biologists in Yellowstone remove the calcium carbonate otolith, or "ear-stone," from dead fish to discover where the fish swam when they were alive. Tom McMahon, a professor of fishery biology at Montana State University, explained that technique: The otolith forms as a fish grows, and incorporates distinctive isotopes from each tributary it visits, so by analyzing it, "You can backtrack on (the fish's) movements through its entire life."

But I've heard a cautionary tone from several biologists over the years. Even Brian Woodbridge, the Swainson's hawk researcher who used early transmitters to discover migrations and threats posed by pesticides in Latin America, said the technology would not have played such a transformative role, if the researchers hadn't done the long-term fieldwork that included banding and watching the birds. Those traditional methods determined the basic population dynamics and the significance of the fact that the hawk's numbers were dropping. "Patterns emerge over time, that you can't get through technology in the short term," Woodbridge said.

Denver Holt, head of the Montana-based Owl Research Institute, had similar thoughts on a sunny day last March, when he drove me to a subdivision north of Polson, Mont., to show me more than a dozen bright white snowy owls -- aka "snowies" -- sitting on rooftops. In the same area, Holt pointed out a black golf-ball-sized owl "pellet" -- indigestible remains of an owl's meal -- lying on the ground. Holt, who has studied snowies in the field for 25 years, often following them to the Arctic where they spend most of their time, concluded that this pellet had been regurgitated by a snowy that had devoured voles. He took out his binoculars and looked through them upside-down, using them as a magnifying glass, to find tiny bones in the pellet. "Hmm, fibula ... tibia," he said, "and here's a humerus," as he pulled out a leg bone the size of a paper match. "Ought to be a skull in here somewhere," he predicted as he pawed through the black mass. And, sure enough, there was.

Long-term field studies like those Holt has conducted are increasingly rare. He believes they bring something unique and powerful to the table, even though they are difficult and hard to fund. "If you are on the ground, touring the field, making observations, you start to see patterns," he told me. "And if you aren't in the field, you would miss the unusual events that happen. If a snowy owl attacked a polar bear or a caribou that was getting too close to a nest or a chick, you wouldn't see that with just (transmitter) technology. You would have beeps on a map that might tell you something was going on, but you wouldn't know what it was." He worries that high-tech will supplant, rather than complement, long-term field studies. "You don't want to totally abandon field research," Holt said. "What you want to do is combine them, try to get the best out of both types."

Ed Bangs, probably the most well-known wildlife biologist in the Northern Rockies, shared his philosophical thoughts over breakfast in Helena, Mont., where we both live. For most of the history of federal wolf reintroduction in the Rockies, Bangs was the chief spokesman and manager; he retired in 2011. Over the years, after traveling with him to several wolf-related meetings and other events, I'd come to believe that he thought more deeply about the work than most of his colleagues. "You never need to go into the field" anymore, Bangs said, given today's technology. "You collar the animal and follow it in real time on the computer. You never see it; you never see where it lives. You can do a wildlife study and never visit the area. ... I became involved in wildlife research because of my passion for wildlife and wild places -- and technology doesn't catch that passion. We need more of an emotional connection with wildlife ... not just technological connections."

We talked about how the new technology encourages many researchers to think there is less need to spend dogged days, weeks and months in the field watching wildlife. Like Woodbridge and Holt, Bangs also believes long-term fieldwork can lead to a deeper, or least different, understanding of wildlife ways and habitat. Some in their camp also fear there has been a steady erosion in the sense of wildness, the feeling of mystery, much as the sense of freedom in the human world is being changed by surveillance technology. In some cases, Bangs warned, the new technologies not only don't further conservation, they may hinder it.

"Conservation involves managing people more than it does wildlife," said Bangs, drawing from his long experience in trying to persuade ranchers and hunters to accept wolves that kill livestock and elk, while also trying to persuade environmentalists that it's OK to shoot and trap some wolves. "Learning more about wolves is almost immaterial to wolf conservation. Some biologists don't even go out in the field anymore. How does it further conservation if you don't know about the people?"

Day by day, the advance of the new technologies raises more ethical questions. With the power to work with DNA growing by leaps and bounds, the revival of extinct species may not be far off. The veteran environmentalist Stewart Brand -- editor of the Whole Earth Catalog and founder of several green organizations, including the Long Now Foundation -- has helped launch a new project called Revive and Restore, dedicated to "de-extinction" of vanished species. The first species Revive and Restore may try to pluck out of the black hole of extinction is the passenger pigeon, the last of which died out in 1914. So far, only preliminary steps have been taken -- the genes of several museum specimens are being sequenced -- but Brand thinks it is doable in the not-too-distant future. In Revive and Restore's first meeting, at Harvard last February, Brand told me, "The practicalities are getting more practical all the time." In Spain a few years ago, in fact, researchers cloned an extinct ibex, a wild mountain goat, though it only lived a very short time.

Even the high-tech collars raise uncomfortable management questions. How far do you go to make a species palatable to people who are antagonistic to it? Collars can measure whether the animal is resting or active, by its heart rate and body temperature. But they can also be programmed to control an animal. Shock collars, similar to those put on ornery dogs, for instance, have been tested on wolves; when the wolves tried to roam beyond a fence of sensors controlled by a satellite, they were shocked. As the whole realm of wildlife conservation grows ever more controversial, biologists have also experimented with wolf collars that have tranquilizers in them, and can be activated remotely. Some ranchers, Bangs said, have joked that such a collar could also be packed with explosives that could be detonated remotely -- the kind of fate that might be in store for prisoners on a totalitarian planet in science fiction. In today's brave new world, or habitat, if things go that far eventually, it wouldn't surprise me.

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Jim Robbins is a longtime New York Times writer based in Helena, Mont., and the author of five books, including this year’s The Man Who Planted Trees. His Times stories over the years included some of the experiences in this essay.

This story was funded with reader donations to the High Country News Research Fund.