Small changes on farmlands could help reverse the steep decline of a grassland species whose joyous chorus once filled the air.
By Cecily Ross
Every spring, the hayfields on our farm come alive when the bobolinks return. The spectacle begins in mid-May as the males gather in great swirling clouds, alighting on the telephone wires and the barely budding trees. A few days later, the females join them and a raucous, exuberant courtship ensues as the males, decked out in their backwards tuxedos, woo the females with the enthusiasm and showmanship of so many feathered rock stars.
For me, the bobolink’s joyous song – a bubbling cacophony of melody floating over breezy meadows (listen to it at http://wildspace.ec.gc.ca/media/sounds/bobo.wav) – is nature’s most eloquent harbinger of summer, evoking in a few bars of musical virtuosity the sweet, idle and seemingly endless landscape of my childhood. Those days are gone, of course, but not the bobolinks.
At least not yet.
One day last spring, I walked across the fields of our 36-hectare farm in Dufferin County with my birding friend Barb, through the thickening crop of timothy studded with buttercups and viper’s bugloss. She marvelled at the dozens of bobolinks putting on their noisy annual show, clinging to weed stalks and wire fences, puffing their neck feathers and spreading their wings, and then careening like low-flying planes over the waving grasses.
“Too bad they’re in such trouble,” she said.
“Trouble?” I replied, puzzled. As we stood there watching them, my bobolinks seemed undisputed masters of their domain.
“Bobolinks nest in the long grass,” said Barb. “In a few weeks, the farmer who leases your land will harvest this hayfield. And when he does, all the baby birds?” – she frowned and shook her head – “bobolink sushi.”
Thus began my personal campaign to save the bobolinks, if only the few that return each year to nest on our fields. The solution seemed simple: ask the farmer, my neighbour David Jones, to delay cutting the hay until the second week in July, by which time the baby bobolinks would be fledged and ready to fly. Not a farmer myself, I had no idea what impact this would have on Dave’s beef cattle operation. And because I anticipated that he would treat my request with the bemused resignation that he reserves for “crazy city folks” like ourselves, who have strange notions of country living, it took me more than a week to get up the nerve to make the call.
In the meantime, I learned a lot about bobolinks. First, I found out that the birds are in danger of disappearing altogether in a few decades if something is not done to protect their nesting grounds.
Bobolinks are grassland birds, which means that in Ontario they nest in hayfields and lightly grazed pastures. Originally denizens of the native grasslands of western Canada, the species moved eastward in the last century as their home habitat declined and the eastern forests were cleared for agriculture. Until the mid-1980s, bobolinks adapted well to the meadows and open fields of south and central Ontario. Today, the province supports about one-fifth of the world’s population of bobolinks, whose breeding range extends from central British Columbia to the Maritimes and in the United States from southern Oregon to western North Carolina. In fact, a map based on Breeding Bird Survey data shows the highest concentrations of bobolinks right in my own backyard: the farmlands of Bruce, Grey and Dufferin counties.
Things were going beautifully for the bobolinks until, in the latter part of the 20th century, agricultural practices changed. In particular, farmers began harvesting their hay more frequently and earlier. Today, cutting dates occur two to three weeks sooner than they did 50 years ago – in mid- to late June, right around the time that the bobolinks’ three to seven mottled, greyish eggs hatch and the tiny newborns are at their most vulnerable. According to the Quebec-based Migration Research Foundation, 96 percent of eggs and nestlings are now destroyed during early hay cropping, either killed by mower blades or scooped up by gulls and other predators when the protective grasses are cut.
Jon McCracken, national program director of Bird Studies Canada, confirms that bobolinks have undergone a “widespread and severe decline in past decades,” and the biggest drop in the last decade is here in Ontario. In the 40-year period between 1968 and 2008, bobolink numbers declined by an average of 2.6 percent per year, an overall decrease of 65 percent. Even more alarming is that the rate of decline has increased decade by decade. In the 10 years up to 2008, bobolink populations dwindled by an average of 7.1 percent per year, resulting in a 50 percent plunge in the number of this species.
“It’s a massive, massive loss in population,” says McCracken, adding, “We are seeing these sorts of declines in all grassland birds in North America.” The cause is the same for all the species: loss of habitat and habitat disturbance.