In this chapter, the book shifts focus to look directly at one of the causes of grassland bird decline--toxins in the environment.
I focus primarily on Carbofuran (Furadan), a strong pesticide that has been killing birds and other creatures for decades. The granular form, particularly attractive to songbirds, was banned a few years ago, after a protracted de-registration process both in Canada and the U.S. Meanwhile, the liquid form remained available for farmers to use until earlier this month when both the American and Canadian agencies finally gave in to public pressure--24 years after scientists first proved that the chemical was killing millions of birds.
image from http://maratriangle.wildlifedirect.org/
The image above shows a lion poisoned in April in Africa's Mara Triangle Conservation Area. The lion had been feeding on a carcass of a hippo that died from eating vegetation sprayed with liquid Carbofuran. A total of four lions were affected. Two died along with five hippos. Apparently, the outrage over these poisonings led rapidly to the American Environmental Protection Agency taking action.
FMC Corp., the makers of Furadan, still says on its web site that Furadan "remains a useful product, vital to the sustainability of agriculture " and that its proper use "does not create a risk to human health, wildlife or the environment."
Propaganda from corporations such as FMC has too often taken the place of science in the public mind, fostering a situation where a destructive pesticide such as Carbofuran can stay on the market years after it was proven to be killing millions of birds. This displacement of publically-funded science with industry positioning is only exacerbated by the Harper government's muzzling of government scientists. The Globe & Mail writer mentions not being able to get a direct quote from Pierre Mineau, the Federal scientist who got the de-registration process rolling in Canada 24 years ago after learning about the effects of Carbofuran on prairie songbirds.
These egregious delays can only happen because information is being kept from the public. If news about the lions and hippos dying had not got out, the American EPA would not have moved on banning the pesticide. And you can bet that if the EPA had not acted, our government agency (the Pesticide Management Review Agency) would not have banned this pesticide either.
The Harper muzzle order on our Federal scientists prevents information from entering the public forum where informed citizens can pressure the government to act on the best research coming from their own researchers. If it is happening with pesticides and wildlife you can bet it's happening with climate change, leaks from nuclear facilities and many other issues.
McCown's longspur was one of my favourite prairie birds to see in cropland near Regina. Until the late 1990s there were still one or two reliable places where I could find them nesting within ten or fifteen minutes of the city. In this chapter of Grass, Sky, Song, I talk about their disappearance, and the decline of the once abundant horned lark on the Regina plains. Many factors have contributed to the loss of these birds, but one that does not get talked about near enough is the transformation in agricultural practices during the last twenty years, coinciding with the decline of these and other birds.
Big rigs like this are becoming the norm in prairie Canada, as farmers get bigger and adopt the more intensive practices of direct seeding and what is called "conservation tillage". Instead of leaving land fallow and tilling it to control weeds, most producers now seed directly in last year's stubble and control weeds with heavy applications of herbicides. Land seldom gets a rest from year to year. Birds such as the horned lark and McCown's longspur were once able to breed in summerfallow, but no longer have that option. horned lark image courtesy of Val Thomas
Horned larks will still attempt to breed in stubble now but the timing of the farmer coming to seed in the spring means that many of their nests are destroyed by the passage of massive seed drills pulled behind four-wheel drive tractors. Thus, what was once fair breeding habitat for the species has now become an ecological trap. Breeding Bird Survey data for Saskatchewan show a yearly decline of 5.6 percent. In Manitoba, the decline is steeper, at 7.83 percent per year.
But that is only part of the effect of the change to these new practices. The larger farm equipment became under the transition from tillage (summerfallowing) practices to "conservation tillage," the more difficult and expensive it became for farmers to leave margins around the edges of their fields or around sloughs and bush. This has meant that fields today are "cleaner," and in general contain less grassy habitat on their edges and fewer sloughs and aspen bluffs. All of this edge habitat once provided nesting and foraging areas for more tolerant grassland birds that once survived on the margins of cropland--birds such as kildeer, western meadowlarks, savannah sparrows, Le Conte's sparrows, and many others. Farmers don't choose these new practices because they want to destroy nature in and around their fields, but end up being drawn in to a cost-price squeeze that pushes them toward a scale and style of farming that in the end is hostile to any plant or creature that does not directly contribute to crop yield. Here is a web page from the Alberta Government's Agriculture and Rural Development department, advising farmers who use these "conservation tillage" or "no till" systems on how they can poison all the ground squirrels, gophers, voles and mice on their land. Birds can be a problem (starlings and blackbirds are mentioned) but, mercifully, there are no recommendations on how to "control" them.
We do not know all of the ways that the plains bison once helped maintain the health of our grasslands on the northern Great Plains, but it seems fair to guess that its role was central and went well beyond the direct effects of grazing. How did their wallows, pockmarking the plains as divots of mud and dust, play into the long term patterns of plant succession and micro-cummunity? Was there anything about their droppings that the prairie has missed since they've been absent?
With more bison on native rangeland than at any other time in the past 120 years, there are now some opportunities to look at these and other questions. The new herd in the West Block of Grasslands National Park is thriving, according to a recent report in the Globe & Mail, and it seems that already grassland birds are taking advantage of the new conditions the bison have created. For example, some songbirds, the report suggests, are already using bison fur to line their nests. Its great insulation value may help egg and nestling survival, which is always an issue for ground-nesting birds, particularly in springs such as this one with late snow storms and prolonged periods of sub-zero temperatures. Meanwhile, sharp-tailed grouse are said to be using grazed down patches of prairie to hold their spring leks. This summer, students will be researching the effects of bison on songbirds in the park.
All very encouraging as evidence that birds and plains ecology in general will benefit from the return of bison. The task ahead of us in coming years is to find ways to work with landowners, stakeholders, consumers and producers to bring an economically workable and ecologically-sustainible vision of large-scale bison range into the light of day.
Hills in the West Block of Grasslands National Park
Source: U.S. Fish & Wildlife The bobolink, a bird of moist meadows that breeds in many states and provinces across North America, is declining in part because of pesticide use in its winter range in South America. Up here, we can help bobolinks out by not mowing fields where they nest until at least July 15.
image courtesy of Northern Plains Wildlife Research Center
I open this chapter talking about one of the "thousand cuts" that are killing grassland birds. The list of predators that birds on remnant grasslands have to contend with is long and varied, but it was a shock to discover that white-tailed deer is on that roster. The image posted above shows a deer with its muzzle in a nest of seven-day old Savannah sparrows. It's a video capture from research done by The Northern Prairie Wildlife Research Center in North Dakota proving that white-tailed deer are eating grassland bird nestlings. Here is a link to the research paper.
Habitat fragmentation gets a lot of attention in the world of bird decline and so in this chapter I use some of Bridget Stutchbury's work on the effects of fragmentation on forest songbirds to speculate on how the same factors may be harming grassland birds. Her take on how fragmentation affects birds has more to do with social behavior and extra-pair copulation than vulnerability to predators and cowbirds. Here is one of the papers she published on gap-crossing and fragmentation.
The spring season of readings and talks is all but over and my last two events, both in Winnipeg, were particularly fruitful. Last Thursday, talking to local naturalists at Fort Whyte Alive, a wonderful nature centre on the southwest edge of Winnipeg, I learned some things that I am mulling over: things about the First Nations people in the prairie provinces using their Treaty Land Entitlement land for agriculture and at the same time considering species at risk and larger environmental questions. The next night, I spoke after a banquet that ended a week of the Canadian Mennonite University's Spring Literary Festival and School of Writing. Afterwards, I had several conversations with people who write and read and think about our alienation from nature and what this means for the human spirit. I had spoken of a new book I've been reading on the topic: Bill Plotkin's Nature and the Human Soul: Cultivating Wholeness and Community in a Fragmented World.
Back home and on the May edition of CBC Birdline on Monday, I found a news release by the Canadian Cattleman's Association on the occasion of Migratory Bird Day, May 9. In the release, Lynn Grant, their environmental director says, "We like to see the waterfowl and song birds in our pastures. It's a sign that the pastures are in good shape." He also advises producers to "keep cattle off the natural pastures so the grass plants have time to really get growing. We like to keep our cows on seeded grass pastures for a while." Encouraging to hear this kind of talk from CCA, although I've always known that the best of our cattle ranchers are solid defenders of prairie ecology and biodiversity. Unfortunately, many farmers who also raise a few cattle on a small piece of native grassland do not follow this advice of grazing their livestock in spring on tame forage until the native grasses have a chance to get established. Too many will release their animals in May into a valley or coulee with some native grass, grazing the prairie at a vulnerable stage, and never allowing it to recover year to year. The prairie suffers from mistimed continuous grazing, and grassland birds arriving for the breeding season have to go elsewhere.
John Carlson, a Montana Bureau of Land Management biologist who appears in Grass, Sky, Song, has one of the best bird blogs on the northern plains. Take a look at this post about Sprague's pipits fighting aerial battles. I would bet these are the first decent images of this species fighting in the air. Male pipits spend a lot of time high above the prairie at this time of year and John estimates that these two were fighting at a height of 100 feet. Here is another shot that appears in John's blog, Prairie Ice: