Free as a Bird

 

The Tragic Loss of Species

Peter McKenzie-Brown

What, exactly, is Canada’s biggest export to America? Conservationists would say “birds,” naturally - for example, the Chestnut-collared Longspur pictured here.

I’ve been a birder for a quarter of a century, and it’s a glorious hobby. One of its great pleasures is that it lures me, my spouse and our birding friends into the natural world, where we train our binoculars on birds of extraordinary beauty and (usually) splendid song. In those years I have identified 133 individual species in Alberta alone – most recently, a Philadelphia Vireo. As we studied the avian world we learned, for example, that 914 avian species occur naturally north of the US/Mexican border. Of that large number, 426 species breed in Canada. For most, our land is their cradle.

As our interest grew, a friend acquainted us with the practice of bird banding. We are among many volunteers who help band beautiful Mountain Bluebirds and Tree Swallows, which breed in the Alberta foothills. Both species winter in the southern USA and northern Mexico. This is because of dramatic reductions in species populations during the early mid-20th Century because of changes in predation, farming, and forestry practices, and competition from such introduced species as the European Starling. This led to the development of “Bluebird Trails” – volunteer-made nesting boxes placed at intervals along highways and byways to provide safe breeding sites. Opportunistic Tree Swallows soon acquired a liking for these nesting boxes, so we band them, too.

Volunteers like us maintain the boxes, keep records of nesting successes, and – if licensed to do so – clip a band on one leg of adult and sufficiently mature nestlings. Our efforts are a miniscule part of a global effort to better understand our avian friends. We attach bands on the legs of the young just before they are about to leave the nest box. We also band adults we capture in the nest. When banded birds are recaptured, or if someone finds a band on their legs after they die, the ornithological community gains a better understanding of their migration patterns, ages, and changes in species behaviour over a well-defined period. The bands themselves neither harm nor hamper the birds.

The practice of bird banding is a logical continuation of birdwatching, which reflects the simple reality that people need nature to be happy – and little in nature is lovelier than birds and birdsong. Bird banding is a remarkable example of citizen science. It involves attaching a small, individually numbered aluminum or coloured plastic tag to the leg of a wild bird. These data are maintained in a central depository, available online. If you recapture a banded bird in or find one dead, email its band number, date, and location to the website given on the band.

Tracking the movements of individual birds and their life histories involves the efforts of countless volunteers. Banders and their assistants tend to be retirees, although professional ornithologists also do the deed. The Canadian Migration Monitoring Network, which has 27 primary sites, tracks the movement of birds during their spring and fall migrations, using both observation and banding. Licensed banders and volunteers are afield before dawn during the migration seasons, erecting fine-meshed nets along known bird migration pathways. They sex, age, weigh and measure and make health assessments of captured birds. Most of Canada’s primary migration paths have seen banding for many years. For example, the Long Point Observatory on the northern shore of Lake Erie began doing so in 1960. Forty-seven years later, its volunteers banded their millionth bird. The long-term, continuous records from these sites track population patterns and species movement in our rapidly changing world. And they demonstrate clearly that many migrant species are declining in numbers.

Most birds are migratory, and the North American Migratory Bird Treaty recognizes that the countries through which they travel on these migrations need to protect them. During the chaos of World War I, American President Woodrow Wilson and King George V of Great Britain signed the Migratory Bird Treaty Act in 1916; two years later, the US passed the Migratory Bird Treaty Act – legislation which protects more than 1,100 migratory bird species by making it illegal to “pursue, hunt, take, capture, kill or sell live or dead birds, feathers, eggs and nests,” except by permit. Most species of birds in Canada are protected under the Migratory Birds Convention Act, 1994 – first passed in 1917, and occasionally updated. This act recognizes Ottawa’s authority to pass and enforce regulations to protect species included in the convention. Similar legislation in America protects species in that country, though the list of bird species protected by each country can be different. Canada’s 1994 update kept our legislation consistent with US standards.

One result? In the 1930s, researchers determined that most birds migrate within the continent through four predictable corridors. This strengthened scientific consensus led to growing efforts to protect boreal lakes and forests, which constitute our biggest hatchery. Taken together, the continent’s tundra and boreal forests export three to five billion birds to the winter ecosystems of the Americas – southern Canada, the 48 contiguous states and as far afield as Mexico, the Caribbean and South America.

Recent technological developments are helping uncover the mysteries of bird migration, yielding detailed data about the hemispheric-scale movements of migratory birds. Most importantly, these systems provide information about what we can do to better protect birds, using increasingly sophisticated technology. For example, satellite tracking and geolocation devices provide detailed accounts of when and where birds move, and the places where they stop. This reveals areas where habitat protection is critical. Compared to banding, however, geo-tracking is an expensive way to obtain data.

Perhaps the most important recent advancement is Cornell University’s development of eBird, an app that provides endless information about our planet’s avian life.  It allows birders everywhere to submit their sightings and counts to a central database. As usage expands and the software becomes more sophisticated, ornithology will develop a greater understanding of the size and distribution of bird populations. Anyone interested in birds and in helping to ensure the species survival can sign up and submit their sightings to the database. A program named Bandit is one of several desktop applications for managing and submitting data for banded birds. Canadian banders use the no-charge software to store data obtained during banding operations until the season’s end, when they transfer their data to an Ottawa agency, which shares it with its US counterpart.

This continent’s ornithologists, with the help of the armies of banders and helpers, long ago established that migratory birds need intact habitats – vast in extent – to survive. A scientific report, Survival by Degrees, shows that 64 percent (389 of 604) of North American bird species are at risk of extinction from climate change. The good news, the report says, is that immediate action can improve the chances for 76 percent of the threatened species. Centuries of bird science show what we can do to protect the birds we love and the wilderness areas we relish. To do nothing to protect our birds and their habitats would be enough to make us birders cry.