Hawks and the city

Rays from a morning's summer sun filter through branches, turning the ground into a jumbled jigsaw of green. Hidden in the shadows, a great horned owl perches, mottled feathers on a body the size of a fat tabby cat blending perfectly with the surroundings. As if on bearings, her head swivels, allowing the giant bird to scan the ground behind with her round-as-saucers eyes.

High above, a mother hawk gazes at five hungry hatchlings vying for space in a nest atop a leaning larch. Where is her mate? Somewhere nearby, perhaps settling into a final glide, red eyes fixed on an unsuspecting sparrow. Day upon day, the mother hawk waits. And several times each day her mate returns, carrying a songbird whose rapidly beating heart has been stilled by the powerful bird's kneading talons.

Fifteen minutes later, the male hawk alights on a stately deciduous tree adjacent to the larch. Gazing up, he calls, as if to say to his mate: "Look what I have for you!" As he pauses with a lifeless sparrow in his clutches, his barred, rusty breast expands and contracts.

Suddenly the angry chatter of another hawk pierces the air. "Kek-kek-kek-kek-kek!"

The hawk loosens his grip on his kill, glancing warily about. The sound is not coming from the nest but somewhere below. As he zeroes in on the sound, he is caught up short by the penetrating yellow eyes of his feared adversary. Hard-wired to respond to the threat the owl poses to his progeny, the hawk swoops from the tree to strafe the bigger bird. In his instinctual act he can be forgiven for dropping his kill. He can also be excused for not seeing the outstretched arm that stealthily retreats behind a tree, the same arm that earlier played the tape that produced the hawk alarm call. The same arm that minutes before stretched a mist net in front of the tethered owl. The same arm that will later free the trapped Cooper's hawk from the fine mesh that it is now tangled in.

All of this occurs far from that mythical place we call wilderness, smack in the middle of British Columbia's second-biggest city, in fact. And it is precisely this incongruous setting that gives the events of this June morning such appeal, for they challenge strongly held convictions that we humans are always a blight, that our actions are invariably bad, that the only effective counter to us is wilderness. Never mind the messy truth, verified by science, that in wilderness parks big and small we're losing species, not conserving them. Landscapes, whether they are officially protected or not, never stay so for long. Which is why ecologists are fascinated with creatures like Cooper's hawks. Why is Victoria, for God's sake, home to such large numbers of these raptors? In a nutshell, it is because the hawks like it here. They adapted to the changes we made and are flourishing. And that is where there is hope. Because if we better appreciate how the wild creatures we profess to care about respond to change, then maybe we can provide enough of what it is they need to survive.

At 5 a.m., the glow from a half-moon turns the oaks a whiter shade of pale. As I navigate a tree-lined and undulating Foul Bay Road, I consider myself fortunate that on this March morning the weather is as far from foul as can be. A thin blue line on the horizon heralds a new day. The advancing sunlight dulls the moon's surface. Stars become lacklustre. Soon even Venus will be gone from sight. My only regret is that I will not greet the dawn with a steaming cup of coffee warming my hands. It could be a cold wait amid the tombstones at Ross Bay Cemetery.

Andy Stewart, who meets me at the cemetery, has played these waiting games before. A biologist with the provincial environment ministry, he has banded more than 1,100 of the birds around Victoria and has a hawklike eye for where 60-plus pairs of them will nest and raise their young. One site is here, a stone's throw from Fairfield Road and a local shopping mall whose parking lot will soon fill with cars.

As we wait, it is inspiring to recall that only four decades ago ecologists feared these birds would disappear. As Rachel Carson warned in her seminal book Silent Spring, chemical insecticides like DDT were robbing our world of birdsong. Raptors were at particular risk because they occupied the food chain's upper rungs, accumulating the chemicals in greater concentrations. As a result, Cooper's hawks faced extirpation-local extinction-particularly in the East. But as Stewart and Wisconsin-based Cooper's hawk expert Bob Rosenfield know, the hawks not only rebounded since the chemical stopped being applied but are thriving.

They are also pleasantly confounding scientists with their ability to adapt to unusual circumstances. In fact, Rosenfield is closely monitoring three different populations, one here in Victoria, the other two in Wisconsin and North Dakota. Although each landscape is unique, all are dramatically fragmented. And for many scientists it is a deeply held belief, bordering on religious conviction, that when you shred "pristine" wilderness into small, dispersed patches you sentence species to death. Well, not always.

Several weeks after our cemetery stop, Stewart recalls encountering just such a bias when reading a scientific journal, an experience that proved the catalyst to what is now a decade-long field study in the Victoria area. In 1993, the Journal of Raptor Research published an article suggesting that New Jersey's Cooper's hawks would disappear.

"The impact of new [suburban] developments near Cooper's hawk breeding habitat will produce forest fragmentation effects, which lower breeding populations of interior bird species, the principal prey of Cooper's hawk in our area," scientists from Rutgers University, the University of Connecticut, and New Jersey's Department of Environmental Protection reported. The trouble was, they were wrong.

Ironically, New Jersey bills itself as the Garden State. Yet Stewart knew that in Victoria the landscape was much like parts of New Jersey, shredded into tiny patches of forest, open areas of lawn and garden, hedgerows and trees. He's been counting and banding Victoria's Cooper's hawks ever since.

"Even biologists are brainwashed to think that humans and animals don't mix, that disturbance is always bad. I did too when I first started," Stewart says. "All of the highest recorded densities of these hawks are now in cities. They're in Los Angeles. They're in Tucson”¦ Yet, if you'd read the literature 10 years ago, you would have got the exact opposite impression."

Much as you would have if you'd read an even earlier article published in 1974 by National Geographic. In it, scientist Noel Snyder warned that Cooper's hawks needed "native wilderness" and "woodland creatures" to feed on in order to survive. He would make similar claims in Condor, a noted journal on avian science. Years later, at Rosenfield's urging, National Geographic published a roundabout mea culpa. Although not saying the previous article was wrong, the magazine noted in a short item how new studies showed the hawks flourishing in the very places others portrayed as death traps.

Back at the cemetery, Stewart tells me that with luck we will see some courting and nest-building activities when the hawks arrive at dawn from their roosts. But this morning the female appears briefly, then flies swiftly away toward a rocky promontory. Moments later, the male alights in a budding tree. In early daylight, his barred, reddish-brown breast shines, offset by dark slate-blue wings and plumelike tail feathers in alternating bands of light and dark grey.

Were his prospective mate here, he would by now be striking the branch with his sharp beak to simulate the plucking of prey. Then the two might fly about, snapping the ends off tree branches, material for a new nest.

"She's thrown us a curve," Stewart says of the female. "She will, I almost guarantee you, nest with this male. But she's going to toy with another male. I've seen quite a few females do this. They court several males. They might even copulate with them. But they have no intentions of staying. It makes quite a bit of sense when you think about it. If one of the males dies, she's got a backup."

Three months later, I spend several mornings with Stewart and Rosenfield as they trap adult hawks and band nestlings. Stewart's wife, Irene, and son Brad often join them, willing conscripts on the urban ecological frontier.

On the morning that the male hawk flies into the net, the arm that reaches in to free it is attached to Rosenfield. Short and of wiry build, Rosenfield is 51 and disarmingly fit. He is also, as Stewart whispers in an aside, "a bit of a maniac". I quickly learn why. After taking several measurements of the captured hawk, Rosenfield casually walks over to the larch, gets a boost from Brad, and climbs toward the nest some 17 metres off the ground. When he gets there, the mother hawk repeatedly strafes him, drawing blood on his forehead and arm. Somehow, Rosenfield retrieves five chicks, places the porridge-coloured birds into a thick sack, and lowers it by rope to the ground, where Andy and Brad weigh, sex, and tag the young birds.

Five is many mouths to feed. And for weeks that task falls entirely to the male while the female-about half again as large and whom the male also feeds-guards the nest. The male's smaller size accentuates his ease of movement. But even so, the element of surprise remains critical to his ability to catch prey. This is one reason why the hawks are so infrequently seen, even though they live in such close proximity to humans. As legendary raptor authority Frank Beebe describes in his richly detailed and illustrated Field Studies of the Falconiformes of British Columbia (falconiformes comprise eagles, hawks, and, of course, falcons), the crow-size hawks "keep cover, often perching well-concealed for hours.

"If, by making a circuitous approach, they can get within range of a prey they will perch, again, well-hidden, until the prospective victim, unaware of the hawk, moves a little away from cover and is momentarily pre-occupied or offguard. Then the attack is made, swift and silent."

One afternoon while I was running in a nearby park, a hawk swooped over my right shoulder, then immediately dropped to a metre off the ground, navigating the twisting pathway before disappearing around a corner. I cannot say whether my presence spooked the hawk's would-be prey or whether the clever bird used me as a foil, hoping that I might flush a songbird. Or perhaps it simply used the dense thickets of snowberry bushes and grasses lining the pathway to move unseen to a new perch. What I do know is that I was witnessing an ongoing evolutionary miracle.

The Cooper's hawk, Rosenfield explains, "is a bird-catcher. He has long legs, relatively speaking, and long toes for grasping things that are very agile, like avian prey. He has a very long tail, which provides for manoeuv?rability through thick vegetation. And he has short, rounded wings like a grouse, which also allows for ease of manoeuvre."

The highly fragmented urban landscape, as opposed to the undisturbed forest, proves a remarkably good fit for the hawks. A proliferation of wooded parks, cemeteries, and back yards provides them with nesting habitat. Hundreds of linear miles of edge habitat-the trees and bushes hemming in homes, schoolyards, and campuses-give them roosts. And gardens, open areas, and bird feeders act as magnets to the smaller birds that the hawks frequently prey on, including introduced starlings and house sparrows, the latter of which often do the wrong thing when pursued: they take cover in bushes. The hawks crash in right behind them "and take 'em out", Rosenfield says with a grim little chuckle.

What continues to intrigue Rosenfield, a professor at the University of Wisconsin at Stevens Point, is that these hawks uncannily adjust to new habitats. In Wisconsin, known for its deciduous forests and riotously colourful autumns, many Cooper's hawks nest in pine plantations. Often derided by environmentalists as "biological dead zones", these dense evergreen patches provide excellent nesting opportunities. And because they are frequently on the perimeter of open areas, they are great launch sites for hunts.

Entirely different circumstances prevail in North Dakota. Cooper's hawks traditionally stay away from more open grasslands or prairies. But in response to long-standing human efforts to suppress fires, trees there are colonizing former grasslands and Cooper's hawks are responding by taking up residence.

And then there are the cities. So significant are they to these once almost exclusively forest-dwelling birds that Rosenfield believes it is in cities where we will see the most dramatic advances in the evolution of this species.

Adapting to altered landscapes is, happily, not just the domain of Cooper's hawks. Just a few blocks from my house, along one of the busiest beachside promenades in Victoria, another raptor that for many people symbolizes wildness and freedom took up residence two springs ago. A pair of bald eagles built a nest high in an elm tree in a residential back yard. Beebe notes that in their hunting habits, food, and even reproductive periods, bald eagles "have evolved to suit extremely diverse situations". They are, variously, "scavengers, carrion-feeders, pirates, fishermen, mammal or bird predators, and they capture the latter either from the air, on the ground, or from the water".

One morning while walking along the promenade, I stopped to ask an eagle enthusiast what she had seen through a huge telephoto lens mounted on her camera. She replied, excitedly, that only minutes earlier the two eagles had pursued a gull off Willow's Beach, hitting it in midair. The injured gull made it to an outlying islet before being snatched by the much more powerful birds. Back at the nest, the mother eagle ripped into the carcass while her offspring clamoured for the innards. As I walked farther along, a scavenging gull, oblivious to the fate of one of its own, pecked through a greasy piece of paper to extract a discarded French fry. From garbage to gull to bald eagle-a food chain as vital to the survival of these big urban-dwelling raptors as the chum salmon that months later will spawn at distant Goldstream Park.

Not far from the eagles' nest, the sound of barking California sea lions can sometimes be heard from several kilometres away. Working together, the mammals, which migrate up the West Coast from California to B.C., herd resident fish toward one another. Some of these same sea lions will later swim across the Strait of Georgia to the mouth of the Fraser River. In distant decades past, the river mouth was far different, a true delta with numerous channels and sandbars. But dyke and breakwater construction long ago ended that. In popular wildlife tours commencing on the lower river in April, you are almost guaranteed to see the visiting sea lions basking on the breakwater, new habitat and an ideal spot for them to take a breather while fishing for oolichan.

Wildlife biologists have known for some time that in North American parks wildlife diversity is declining. The biggest losses are in smaller, more isolated parks. But they're occurring in big parks too, as U.S. biologist William Newmark reported in a landmark study in the 1980s. Should we throw up our hands, then, and give up? Stewart and Rosenfield suggest not. Although not all species display the remarkable ability to adjust as do Cooper's hawks, bald eagles, and sea lions, the truth is that given space and time, many species do adapt, often quickly. The more we can learn about how they do, the better able we will be to intervene in appropriate ways.

Furthermore, change, and our ability to initiate it, may be precisely what is needed to ensure the survival of some species in certain ecosystems. Take grasslands. In all of the justified concern over our diminishing old-growth forests, one of the things that often is neglected is that too many trees in too many places are a bad thing. Grasslands remain one of our most endangered landscapes, in part because of farming and urban developments, but also because of our zealous suppression of fires. By doing our best to stamp out fires, we now have trees encroaching on grasslands all across North America. The new trees look good-and they are good for certain species, North Dakota's Cooper's hawks being a good example-but they are bad for a host of grass-nesting birds, rare and endangered burrowing owls, and browsers such as wild sheep.

We can continue to suppress fires out of a belief that they are destructive or we can let lightning strike and let the fires burn where they may. Or we can deliberately set our own fires and attempt to influence when and where they burn, as many First Nations people did prior to Europeans arriving and stamping out the practice. But whether we leave things alone or actively intervene, there will be consequences. There is no such thing as a steady state.

In our ongoing struggle to protect biological diversity, we face difficult choices. There will be winners and losers whatever we do. Clearly, many species are threatened with extinction-mountain caribou, northern spotted owls, and Vancouver Island marmots being three high-profile examples-because we have not respected how they respond to disturbances, both natural and human-caused. But it is folly to lose sight of the fact that some of our actions, intended or not, allow others species to flourish. The great challenge before us is accepting responsibility for being environmental stewards and making fundamental choices about how we alter habitats to achieve desired outcomes.

"Nothing stays the same," Rosenfield says at one point. "And, by the way, which 'pristine' times do you want to talk about? The 1840s? The 1730s? Change is the norm, and you have to reevaluate your values as ecological realities change. A lot of people don't want to see things that way. But in the face of ever-present change, your values, to a certain extent, have to alter too."

Rosenfield and Stewart quickly snag another hawk in a net erected on the banks of a stream whose swelling waters run brown from spring runoff.

After examining his capture, Stewart gently pushes the bird's feathered breast against my ear. I close my eyes, losing myself in the sound of the hawk's rapidly beating heart and the feel of his open beak grazing my scalp.

Each bird has a story. Last year, this male and his mate lost their young when a windstorm turned their nest into cascading twigs. Typically, males don't move far, even following such disasters. Their territorial affinity is strong. But this one moved farther than Stewart had ever seen. Perhaps stronger suitors pushed him out. Or perhaps he wasn't the right fit. (In Wisconsin, breeding hawks tend to pair by size: big females with big males, smaller females with smaller males. Ongoing study by Rosenfield and Stewart will determine whether the same is true in Victoria.) In any event, the hawk settled here, some 3.5 kilometres from the previous nest site.

After telling me this, Stewart places the hawk into my right hand. The bird's feet press flat into my palm. My thumb grips his left wing, my four fingers his right. "Toss him like a football," Stewart says. And as I do, his wings open and he flies off into a nearby fir.

Later I learn that a car hit the same hawk a day after its release. Luckily, he survived to see another day. Others aren't so fortunate. Collisions with cars and building windows are common. Life here has its dangers, but apparently not enough to dissuade these avian residents. This year alone, 32 adult hawks are caught and 114 young are banded, a record in Stewart's ongoing study.

This new frontier has what the birds need-not least of all us.