In his classic book A Sand County Almanac, Aldo Leopold wrote of how winter might look to various animals in cold climates like ours. For a meadow mouse, our warm, nearly snowless January would have been a disaster. Meadow mice spend the summer collecting grasses and storing them in caches on their home territories. These caches are their principal winter food. They scurry from cache to cache along runways on the ground. If snow does not come, their runways are exposed to the eyes of hungry predators. Under a sheltering blanket of snow, the runways become secure tunnels. "To the mouse," Leopold wrote, "the snow means freedom from want and fear."
Rough-legged hawks feast in warm Januarys. The snow hides the meadow mice; a warm winter exposes them. To the hawk, Leopold wrote, "a thaw means freedom from want and fear."
"One man's Mede is another man's Persian," as George S. Kaufman once observed, and nowhere is that more true than in nature, where every dark cloud has a silver lining and every silver lining has a touch of gray. Almost every event we call a natural catastrophe is actually a boon to something or other. I was reminded of the double-edged quality of natural events recently while reading a manuscript titled "The Yellowstone Wildfires of 1988 and What Really Happened to the Birdlife." The manuscript was written by Terry McEneaney, an ornithologist on the park staff and author of Birds of Yellowstone, a detailed birding guide to the park.
McEneaney was in the park throughout last summer, watching the birds adjust to the radical changes that were reordering their world. Some of what he saw was tragic. On August 11, sitting in a boat on Yellowstone Lake, he watched as a fire swept through the pines at the water's edge and engulfed an osprey nest containing two nestlings too young to fly.
The adult birds stayed by the nest as the flames approached. Then the male began to make repeated flights to the lake, returning each time with a fish in his talons. He carried each fish to the nest. The female stayed at the nest, frantically feeding the nestlings. It was as if they were trying to stuff the young so full of food that they would instantly grow flight feathers.
As the flames swept ever closer, the male began calling the young, the sort of call osprey parents use to coax young from the nest. The female stayed at the nest until the moment when the nest tree itself caught fire. And as the fire incinerated their nest, the parents circled just above the flames, still calling.
McEneaney also helped rescue a common loon from a dry sewage lagoon near Old Faithful. The bird had apparently been disoriented by smoke and had mistakenly thought the lagoon had water in it. Loons cannot take off from dry land, so once the bird landed, it was marooned.
With the help of other rangers, McEneaney captured the bird. He took it home and released it in his bathtub, where the bird made a few dives and then began preening. When McEneaney placed a realistic loon decoy in the tub, his captive began yodeling, and before the night was out, it tried to mate with the decoy. The next morning, McEneaney released the loon on Yellowstone Lake.
Stories like these have a powerful effect on all of us. Anyone with children can imagine the horror of helplessly standing by while your offspring are burned to death. Of course objectivity demands that we not try to guess at the internal mental state of a bird. We cannot know what they are feeling or even if they have any feelings. My own guess is that they do. The great ornithologist Margaret Morse Nice once said that her long study of birds had convinced her that they had little intelligence but powerful emotions. The ospreys probably felt as distressed as they looked.
So for that pair of birds, and especially for their unfortunate offspring, the fire was a disaster. But for many other raptorial species, it was a bonanza. The raptor frenzy, as McEneaney calls it, took advantage of all the mice, chipmunks, ground squirrels, lizards, snakes, and other small creatures that had to flee their usual shelters to escape the fires.
McEneaney reports that he had never seen so many birds of prey in one place. "Bald eagles, golden eagles, ospreys, peregrine falcons, prairie falcons, kestrels, Swainson's hawks, red-tailed hawks, northern harriers, goshawks, Cooper's hawks, sharp-shinned hawks, and even great gray owls were taking advantage of the fleeing and/or displaced prey. It was most impressive in the open meadows where the actions and interactions were more observable."
Hawks, owls, and eagles weren't the only birds drawn to the fires. "Common raven, whooping crane, sandhill crane, and great blue heron were working the open meadows just in front of the active wildfires," McEneaney writes. Predatory mammals such as coyotes and badgers were seen doing the same thing, and it is likely that bears made a similar grab for whatever was available.
McEneaney was most surprised by the appearance of large numbers of ferruginous hawks in the park. "Normally," he writes, "one is hard pressed to see ferruginous hawks at all in Yellowstone." But on one day, September 7, he saw more than 40 of the birds feeding on voles and pocket gophers in open meadows near advancing fires.
The ferruginous hawk is a grassland bird, and fires are common in grasslands. McEneaney surmises that the birds respond directly to the visual stimuli of a rising column of smoke, flying toward it because they know fires mean food. With more than 40 birds visible in a single day in a place where the species is rarely seen, we can guess that the Yellowstone fires attracted ferruginous hawks from hundreds of miles away.
The raptor frenzy could have been predicted. Predators have been seen in similar actions many times. They gather in front of the flames on the plains of East Africa and on the llanos of South America. But McEneaney did not expect the large numbers of seed-eating birds that moved into burned areas as soon as the flames subsided. Red crossbills, pine siskins, pine grosbeaks, and Clark's nutcrackers were the most common of these.
The bonanza that drew them was provided by the serotinous cones of the lodgepole pine. The cones of conifers consist of rows of scales. Under each scale is a seed. Serotinous cones remain on trees for many years, their scales tightly closed by a resin. The heat of a fire melts the resin, opening the cones, releasing the seeds, and providing a feast for the birds.
This mixture of good and bad will continue in the future. Birds such as the sage thrasher, golden-crowned kinglet, Williamson's sapsucker, and boreal owl all lost habitat through the burning of sagebrush and mature forest. Three-toed woodpeckers, mountain bluebirds, tree swallows, and others will increase in numbers, for they like young forests.
The National Park Service has been accused by its critics of playing God in Yellowstone. The phrase is catchy, but the criticism misses the point. The unfortunate fact is that we can't avoid playing God in Yellowstone and in most of the rest of the world as well. Whether we decide to suppress fires, set fires, or let wildfires burn, we are substituting our judgments for the natural processes that once sustained wild creatures of all sorts. The question is not whether we should play God, but how we go about getting better at it.
I have only a faint notion of what is required to make this improvement happen. Certainly a part of it is to try to understand nature on its terms rather than on our own. Nature is endlessly creative and endlessly destructive. It has no regard for individuals, and it does not consist of aggregations of individuals. We can't preserve nature by rescuing osprey chicks from burning nests or whales from icebound harbors.
The one entity that seems to endure in nature is the ecosystem, the bewilderingly complex web of relationships that creates a home for every plant and animal. The ecosystem is the perfect example of a whole that is greater than the sum of its parts, and the preservation of ecosystems must be the goal of all our relations with the natural world.
Ecosystems did quite well on their own until quite recently. The enormous explosion in human consumption, the massive intrusion of humanity into every part of the world, is cutting the web of relationships, removing so many parts that the whole cannot continue to function--hence our need to play God. We cannot avoid intervening in Yellowstone, just as we cannot avoid intervening at places like Ryerson Conservation Area in Lake County, where an overabundance of deer threatens the stability of the ecosystem. And in every case, our intervention must as closely as possible imitate the natural processes whose functioning has been impaired by our overwhelming presence.
We need to refocus our moral thinking about nature. We need to realize that we cannot save the deer at Ryerson Conservation Area by allowing them to destroy the trilliums, because the lives of deer and the lives of trilliums are mutually dependent. We need to realize that while saving a few whales from the ice may make us feel good, it does less for whales, and all the other creatures of the sea, than halting the dumping of our poisons into the oceans. And we need to understand that the burning of Yellowstone was a horror to some ospreys but a glorious gift to three-toed woodpeckers, a holocaust to an ancient lodgepole pine, but an opportunity to the seeds held in the cones of that pine.