When Wendell Berry envisioned his geese on their intuitive journey, their destination was likely intact and well provisioned to meet their needs. For the thousands upon thousands headed to the Arctic, along with countless other migratory birds, the stopover grounds in Canada's boreal forest provided a vast and undisturbed span of clear lakes and ponds, nesting sites, safety. The ancient faith was sound and true.

Now a few decades have passed, and a portion of this once untrammeled refuge has become the site of destruction on a scale almost impossible to imagine. In northern Alberta, where all four of North America's major flyways converge to bring more than half the continent's migratory birds each spring, a handful of enormous oil companies are mining the tar sands.

The tar sands are pretty much what they say they are, a thick, sticky form of crude called bitumen, with a texture like soft asphalt, mixed with sand, clay, and water. Because of the low grade, extreme processing, and vast amounts of energy required to extract and refine this form of oil, it was long rejected as a source of fuel. But as lighter, higher grade crude has been depleted, the tar sands have come to look more attractive to the oil companies. Today the tar sands contain the world's third largest proven oil reserves, after Venezuela and Saudi Arabia.

The first mine began operation in 1967, but rapid development began after 2000, when the price of oil began to climb. The Alberta tar sands are currently producing about 2.3 million barrels of oil per day, with plans to increase that to four million barrels per day by 2024.1 The area set aside as an industrial sacrifice zone is roughly the size of Florida, and all of it has been hacked out of the boreal forest and drained wetlands.

Bitumen is mined by two methods, each calamitous to bird populations. What is close to the surface, some 20% of it, is strip mined, using "truck and shovel" open pit mining, except that the truck is 25 feet high and the shovel can fill it in four bites. Each barrel of bitumen requires some 12 barrels of hot water mixed with caustic chemicals to separate it from the sand and clay. A quarter of that highly-contaminated brew ends up in tailings ponds, vast murky pools of sludge containing phenols, arsenic, mercury, carcinogens such as polycyclic aromatic hydrocarbons, and fish-killing naphthenic acids. This sludge is held in the ponds indefinitely by dams hundreds of feet high. Just one of these dams is the second largest dam in the world, exceeded only by China's Three Gorges Dam, and holds enough sludge in that one pond to fill an estimated 160,000 Olympic swimming pools.2

To the several varieties of geese, tundra swans, endangered whooping cranes, and many varieties of ducks that nest in these wetlands or stop over on their way farther north, these tailings ponds not only look welcoming, but in colder weather they are the only waterways that are icefree, and therefore appear to be first choice real estate. But woe betides the bird that lands there, as it promptly becomes coated in oil and in most cases drowns.

The oil companies are required by law to take measures to avoid this situation. These measures include scarecrow-like figures, called a Bit-U-Men, stationed around the lake, and propane-fueled cannons that fire repeatedly to scare birds away. They are effective to a point, though they fall well short of solving the problem. And a single foul-up can have disastrous results, as happened in April 2008, when a delay in activation of the equipment resulted in more than 1600 ducks landing on a three-kilometer-wide waste pond.3 Nearly all of them died.

The remaining 80% of the tar sands are deep underground, requiring the drilling of wells and the injection of steam to make the bitumen easier to extract. The accompanying construction of a vast network of drill pads, pipes, compressor stations, and power plants will ultimately have a much greater impact on migratory and resident birds than even the tailings ponds, due to the sheer scale of the project and the amount of habitat lost.

Downstream from the tar sands, the great rivers of Alberta converge in the Peace-Athabasca Delta, a freshwater wetland which is used by as many as a million birds at one time. But since the early days of the tar sands operations, summer water flow has substantially decreased, thanks to climate change and massive water usage by tar sands operators. Large portions of the wetlands simply dry up, with an unfortunate outcome for ducks and geese.

Canadian and U.S. scientists, examining a variety of possible scenarios, have projected that the planned development of the tar sands may claim as many as 160 million birds in the next 30 to 50 years.4 Apart from the massive impact on ecosystems, the removal of such numbers of birds from our skies staggers the imagination.

There are, of course, other enormous problems with developing the tar sands. Spills have been an intractable problem. Pipelines carrying ordinary crude produce hundreds of spills every year; but diluted bitumen, or dilbit, is more toxic and corrosive, and the pipeline systems are more complex. The spill in 2010 of over a million gallons of dilbit into Michigan's Kalamazoo River, and the botched response, presented a scenario that could become all too common, complete with inept oversight and lax safety regulation.5

Most critically, production of synthetic oil from bitumen is an exceptionally intense source of greenhouse gas emissions. Because of the energy required to extract and process it, the production of each barrel generates three times the emissions of a barrel of conventional oil. And the tremendous investment in the infrastructure required to fully develop the tar sands would divert funding from green energy projects, and lock much of the world into carbon-based fuels for a great many years to come.

And birds are not the only wildlife to feel the impact of the mining. Woodland caribou, for one – already on the threatened list – are declining in the area, and on track for extinction.6

Some efforts have been made to regulate the impact of the tar sands on bird habitat. Canada's Migratory Birds Convention Act prohibits the killing of birds by sliming them with toxic waste. Yet in the wake of the 1600-duck disaster, Environment Canada, the nation's environmental protection agency, considered solving the problem by making it legal. Such maneuverings were not uncommon during the Harper administration, which sometimes altered environmental legislation and shuttered agencies in its zeal to promote unhampered tar sands expansion.

In 2009, the Energy Resources Conservation Board mandated a changeover to a dry tailings process, intended to reduce the growth of the tailings ponds. However, technical problems and industry compliance issues interfered with meeting the goals.7 The directive was suspended in 2015, and plans have been made to take a different approach to achieving these goals, with substantial public input. At the same time, new rules have been put in place for managing water levels in the Peace-Athabasca Delta and its rivers, restricting water use by mine operators when levels are low, and guaranteeing adequate levels for the traditional activities of the Aboriginal peoples.8

In the meantime new pipeline proposals have sprouted in all directions, and increasingly the public has taken an active role in opposing them. A large consortium of First Nations on the Pacific coast has mounted a concerted and persistent opposition to the Northern Gateway pipeline, which would move vast amounts of dilbit across their salmon streams and bring megatankers through the narrow and treacherous coastal waters to carry it overseas. When Canada’s new Prime Minister, Justin Trudeau, took office in 2015, he banned tanker traffic along British Columbia’s North Coast, essentially halting this project. The Keystone XL pipeline, which would have been built across several states in the U.S., was rejected by the Obama administration in 2015 in part because of vigorous protests by farmers and ranchers who didn't want the risk of toxic leaks in their watersheds, and by sustainable energy advocates who didn't want the long-term commitment to carbon-based fuels. Other proposals still under consideration include TransCanada’s Energy East and Kinder Morgan’s Trans Mountain, both of which are all-Canada routes, one to either coast.

The fate of these projects may not be known for years. Meanwhile the mining goes on. And so does the effort to ensure that this most vital habitat will not be reduced to a denuded landscape pocked with lakes of toxic sludge.

1Pembina Institute. http://www.pembina.org/oil-sands/key-facts Accessed 13 Apr 2016.

2 Nikiforuk, Andrew. TarSands: Dirty Oil and the Future of a Continent. Toronto: Greystone Books, 2010.

3 CBC News. "Syncrude guilty in Alberta duck deaths." Online. 25 June 2010. http://www.cbc.ca/news/canada/edmonton/story/2010/06/25/edmonton-syncrude-duck-trial-verdict-expected.html

4 Wells, Jeff; Casey-Lefkowitz, Susan; Chavarria, Gabriela; Dyer, Simon. "Danger in the Nursery: Impact on Birds of Tar Sands Oil Development in Canada's Boreal Forest." 2 Dec 2008. http://www.nrdc.org/wildlife/borealbirds.pdf

5 National Transportation Safety Board. "Enbridge Incorporated Hazardous Liquid Pipeline Rupture and Release, Marshall, Michigan, July 25, 2010." http://www.ntsb.gov/investigations/AccidentReports/Reports/PAR1201.pdf

6 Pembina Institute. http://www.pembina.org/oil-sands/key-facts Accessed 13 Apr 2016.

7 Pembina Institute. https://www.pembina.org/reports/tailings-plan-review-report.pdf Accessed 13 Apr 2016.

8 Alberta Government. “Alberta strengthens environmental protections in the oil sands.” 13 Mar 2015. http://www.alberta.ca/release.cfm?xID=37850C9372213-0699-8D26-F5941693BB890E3E Accessed 13 Apr 2016.