Bobolink Conservation Strategies

Thanks to Diane G for telling me about this article:

Songs of the Bobolink

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.

The plucky bobolink has the longest migration route of any songbird. In July and August, the males abandon their diet of insects and larvae that sustained them through the nesting season, shed their formal dress and take on the muted hues of the females as they all fatten up on seeds before embarking on the long, treacherous journey to their wintering grounds in the pampas of southern South America – a round trip of approximately 20,000 kilometres. On the way, the birds run a gauntlet of hazards, starting with angry rice farmers in the southeastern United States, where the species is known as the rice-bird and is shot and poisoned in the hundreds of thousands as an agricultural pest. In Jamaica, the seed-fattened bobolinks are called butter-birds and are hunted and sold in the local markets as food. Further south, the birds – back in their bright plumage – are prized for their beauty and effervescent song, and are caged as pets in the fashionable salons of Buenos Aries and Lima.

When I learned all this, asking my neighbour to delay his hay cutting seemed the least I could do. But there was a catch. “The nutritional quality of the hay declines the longer you wait [to harvest it],” McCracken tells me, “though with a delay of a just week or two, the decline is minimal.” Not enough to worry a beef farmer like Dave, but of some concern to dairy farmers whose livestock has higher nutritional needs.

The good news, according to McCracken, is that “by delaying cutting by one week or 10 days, you go from zero percent nesting success to a success rate of 80 percent or more. It’s a remarkable change, and it would be a significant thing for a farmer to do.” Many farmers, McCracken adds, are unaware of the toll early hay harvests take on these birds. That is why it is crucial to raise awareness about the plight of the bobolink and other grassland species, such as the grasshopper sparrow and eastern meadowlark (see sidebar at left), all of which are under pressure from changing agricultural practices. The Henslow’s sparrow, for example, has been reduced to fewer than 50 pairs in Ontario, and various groups are now fighting to save this small, shy bird.

“It would be good to get the word out to farmers and landowners,” McCracken continues. “I think a lot of farmers do care about birds. They are interested in being good stewards of the land.” Besides, he points out, “bobolinks are the farmer’s friend. They eat vast quantities of harmful insects and [at least in Ontario] they do no harm.”

McCracken suggests that a mechanism should be available to compensate farmers for any losses they might incur from delaying their harvest. To find out if such programs exist (in case my neighbour balked at my request), I called Andrew Graham, program manager for the Ontario Soil and Crop Improvement Association (OSCIA) at his Guelph, Ont., office. OSCIA disburses funding under the provincial government’s Environmental Farm Program. Graham said that while his group is committed to helping farmers protect wildlife habitat on farms – by offering subsidies to fence livestock out of woodlots and wetlands, for instance – it will not pay a farmer to delay hay cutting.

OSCIA distributes material on the impact of hay cutting on birds, but it stops there. “I have no problem at all with trying to persuade farmers to delay cutting their hay,” Graham tells me. “Our problem is coming up with a fair way of sharing costs [with the farmer] in something like this.” The only program he is aware of that might apply is one for upland and riparian habitat management under the Canada-Ontairo Canadian Farm Stewardship Program. This offers to pay 50 percent of the cost (up to a maximum of $20,000) to farmers wishing to take a portion of cropland out of production and convert it to native species of forest, shrubs or grasses.

“It’s not widely used,” he admits.” And then, almost by way of apology, he adds, “We can’t do everything.”

Given that the environmental bureaucrats were not addressing the well-documented decline of the bobolink, I was beginning to wonder if anyone besides me cared at all. I called my friend Barb the birder, and she suggested I contact her friends, Frances and Donald MacFarlane, who live on 30 hectares of derelict farmland near Shelburne, Ont. Bobolinks, Frances tells me, were there in great numbers 18 years ago when the couple purchased the property.

“They were such fun, so exuberant,” says Frances, that the MacFarlanes were disappointed when the birds failed to come back a few years later. “We asked around,” she says, “and decided that it was because the hay hadn’t been cut for a few years. So we decided to cut the grass once a year, in October, long after the bobolinks have gone – and sure enough, they returned in the spring.”

Apparently, bobolinks prefer habitat that is mowed regularly, just not during June, which, I was only too aware, was fast approaching as I worked up the nerve to call Dave and deliver my save-the-birds speech.

“It’s because of the bobolinks,” I explain to Dave after asking him to delay the hay harvest on our fields.

“Bobolinks,” he says. “Is that what you call them?”

To my delight, he seemed almost relieved by my request and proceeded to describe the way gulls follow his tractor, swooping in and plucking the helpless fledglings as their nests are exposed by the mower.

“I’ve always hated that,” he tells me.

And so last year, Dave delayed cutting our hay until the end of the first week in July. By then, the male bobolinks’ jubilant chorus was over; so was the hard work of feeding their clutches of demanding young. The males had begun to moult and were now almost indistinguishable from their mates. I had no way of knowing, as I looked out over the round bales turning golden in the midsummer sun, whether the baby birds had survived. But I like to think they did and that they will return in the spring, bold and beautiful and ready to begin again.

I know my land is not much – a few fields in a far corner of Dufferin County that hereafter will be a haven where a few dozen bobolinks can raise their young. But the effort is worthwhile, if only so that my as-yet unborn grandchildren may one day be able to lie in the long grass on a cloudless June day and listen to the bobolinks sing.




All about Bobolinks

Some facts about a fascinating bird: male bobolinks arrive in Ontario in mid-May and set about establishing their territories in open fields. Females join them a week later. Males defend their turf aggressively by singing and chasing away rival males. Actual physical combat between them, however, is rare.

Bobolinks are a highly dimorphic species – the males and females look very different. During the breeding season, males are a sleek black with a yellow head patch and bold white patterns on their backs. However, before fall migration, they moult into a nondescript striped brown plumage like that of the females.

Bobolinks are polygamous – a single male will often mate with several females in his territory. He will, however, help with feeding the young only in his primary nest. “Helper” birds of either sex (usually younger birds that have not paired off) assist in feeding the other nestlings. Bobolinks build their nests on the ground, hidden in long grass. The females lay three to seven blue-grey eggs speckled with reddish brown. Incubation takes approximately 13 days; hatching occurs between June 7 and 20. The fledglings leave the nest before they are ready to fly, at about 10 days old. They are not capable of sustained flight until they are 16 days old.

The summer diet of bobolinks consists mainly of insects, including beetles, grasshoppers, caterpillars, wasps, ants, spiders and millipedes. They also eat some weed and grass seeds. During migration, they feed heavily on rice and millet, and are considered a major agricultural pest in regions where these crops are grown.

The species is one of the few songbirds that have two moulting periods. One occurs on their wintering grounds in South America, beginning in late January, and results in the males’ showy spring plumage. The second moult takes place in late July, when the males revert to basic brown and white.


Grassland birds

With its distinctive song and plumage, the bobolink is the perfect poster species for the ongoing effort to protect North America’s grassland birds, many of which are declining steeply in numbers. In Ontario, the threatened species include the vesper sparrow, grasshopper sparrow, Henslow’s sparrow, Le Conte’s sparrow, sedge wren, horned lark, upland sandpiper, short-eared owl, eastern meadowlark and western meadowlark.

According to the U.S. State of the Birds, a comprehensive report produced in 2009 by thirteen U.S. conservation and wildlife agencies (including The Nature Conservancy), grassland birds “are among the fastest and most consistently declining birds in North America.” The main cause of their decline is loss of habitat. Ideal nesting grounds for these birds are the native prairie grasslands that once stretched across the continent. The birds build their nests – usually shallow open cups of grass and weed stems – on the ground, hidden among thick grass and weeds. In the past 100 years, however, 95 percent of the tallgrass prairie in North America has been converted to agricultural uses. Many grassland species adapted well to the hayfields, pastures and lush fallow fields that resulted, but intensification of agriculture in the past 20 years is taking a severe toll on their numbers, and species declines of anywhere from 37 percent to 78 percent have occurred since 1968.

How can you help? Spread the word and, if you are a landowner, take steps to ensure that hay cropping is delayed, ideally by a week to 10 days. Doing so will ensure that most of the fledglings have left the nest, preventing their almost certain death from the mower blades or predators. Any delay in cutting will benefit nesting grassland birds by increasing the percentage that fledge successfully.




To find out more about bobolinks

A good place to see bobolinks and other grassland birds in Ontario is at the Carden Plain, a rare alvar habitat where other endangered species, such as the loggerhead shrike and the Henslow’s sparrow, also live. The plain is located about two hours north of Toronto. Alvars are natural open habitats with thin soil over a rocky base. BirdLife International designated the Carden Alvar as an Important Bird Area (IBA). About 238 bird species, 450 plant species, 142 butterfly and dragonfly species inhabit the alvar. For more information and directions, visit the Carden Plain IBA website, www.cardenplainimportantbirdarea.com.





You can also learn more about bobolinks from these sources:

Bird Studies Canada: www.bsc-eoc.org

Migration Research Foundation: www.migrationresearch.org/research/grassland.html

Ontario Field Ornithologists: www.ofo.ca

Environmental Canada’s Migratory Bird Conservation: www.cws-scf.ec.gc.ca/birds/trends/disclaimer_e.cfm

Atlas of the Breeding Birds of Ontario: www.birdsontario.org/atlas/atlasmain.html

Canadian Migration Monitoring Network:

www.bsc-eoc.org/national/cmmn.html

Ontario Partners in Flight:

www.bsc-eoc.org/PIF/PIFOntario.html

North American Bird Conservation Initiative: www.nabci.net

Partners in Flight – U.S.: www.partnersinflight.org

Wildlife Watchers Programs: www.on.ec.gc.ca/wildlife/programs-e.html

Wildspace Ontario: www.on.ec.gc.ca/wildlife/wildspace/intro-e.html