Bird Banding Builds a Healthier World
By Peter McKenzie-Brown
In fall, they fly south through the US. Many stop when they
reach the Gulf of Mexico, but not all
. Almost incredibly, they fly across the Gulf of Mexico to the Yucatan peninsula – an 800 km, non-stop flight that would seem to require more calories than their three-gram body weight could provide. Though born in Canada, say, they make the same beelines to their winter homes. They may even return to the same garden, year after year. We know that because of bird banding.
I’ve been a birder for years. The hobby lures us into the natural world to watch species often of extraordinary beauty and splendid song. Besides birding as a hobby, in recent years, I have served as bird-banding assistant to my friend Bill Taylor. Bill is a certified bander, and on trips into rural Alberta I am often his helper. We are among the hundreds of volunteers who help band beautiful Mountain Bluebirds and Tree Swallows at breeding sites in the Alberta foothills.
Dramatic reductions in the populations of bird species because of changes in predation, farming, and forestry practices are the backstory to our banding activity. In Alberta, bird-loss led to the development of “Bluebird trails” – volunteer-built nesting boxes placed at intervals along highways and byways to provide safe breeding sites for the Bluebirds. Opportunistic Tree Swallows face less risk, but acquired a liking for these boxes. The result? Ironically, on our Bluebird Trail we mostly band Tree Swallows – keeping comparable records for each species: nesting successes, nestlings banded, age and gender of the chicks. When we capture adults, we band them, too.
Our efforts are a miniscule part of a global effort to understand and assist our avian friends. We attach bands on the young birds’ legs just before they are about to leave their nest box. If anyone recaptures a banded bird, or finds a band on their legs after they die, that band provides information on how to report the date, time, and place. This information helps the ornithological community better understand migration patterns and changes in behaviour over well-defined periods.
Banding is a logical continuation of birdwatching. Taken together, they enhance the simple reality that people need nature to be happy – and little in nature is lovelier than birds and birdsong in the wild. Banding practices around the world help our avian friends, but only because of the vast international machine in which each bander is a tiny, tiny cog.
Banding requires armies of volunteers – the heartbeat of “citizen science.” In Canada, 27 primary sites track birds during spring and fall migration, using both observation and banding techniques. Licensed banders and countless volunteers show up before dawn during migration, capturing specimens in fine-meshed “mist nets” set up for the occasion.
Natural Resources. For the nations of the Americas, birds are a shared resource. The U.S. and Canada coordinate their banding work through the North American Bird Banding Program, which links the Canadian Wildlife Service Bird Banding Office with America’s labs. These organizations cooperate closely – especially on species that migrate within and through North America. However, bird banding takes place across the world, and both Canada and the US collaborate with other countries. Over the course of a normal year, 914 species of wild bird occur naturally north of the US/Mexican border. Of these, 426 species reside in Canada for part or all the year. But let’s go back to the beginning.
In North America, John James Audubon and Ernest Thompson Seton were pioneers in bird tracking, although their methods of marking birds were primitive. To determine whether the same bird would return to his farm, in 1805 Audubon tried tying silver threads onto the legs of young Eastern Phoebes. His interest grew, and he began exercising his considerably intellect and artistic talent to write and design the New World’s most famous bird book, The Birds of America, in 1839. Later to the game, in Canada bird marking seems to have begun in 1882, when Seton marked Snow Buntings caught on his Manitoba farm – with ink! – to see whether they would return the following year.
Banding proper, however, dates to 1899. In that year Danish schoolteacher Hans Christian Cornelius Mortensen started using aluminum rings on European starlings. Within two decades, banding had spread across western Europe and had begun in Canada. Federal programs began in the U.S. (1920) and Canada (1923) pursuant to the 1918 Migratory Bird Treaty agreed between the two countries. Sadly, that treaty reflected the then-recent extinction of the Passenger Pigeon. Indigenous to this continent, these birds may have numbered seven billion when Europeans began to settle. By 1900, they were virtually extinct. In 1914 Martha, the last of her species, died in the Cincinnati Zoo.
Banding on a Big Scale. In recent years, the use of mist nets has enabled banding to take place on a big scale. These nets date back to 17th century Japan, according to an academic article in a 1982 issue of the North American Bird Bander. Today’s birders would abhor their purpose: to catch birds for food. The technique arrived in North America after WWII, after which birders around the world began using them as a critical banding tool. Ornithologists and their supporters set up these nets during critical migration times along key migration routes. An example is Ontario’s Long Point Observatory on Lake Erie, which began banding during migration in 1960. It banded its millionth bird only 17 years later.
The long records of the bird banding community are vital to understanding changes in avian populations and species movement in a rapidly changing world.
The banding equipment needed depends on the species of bird in question. One must decide what species of bird to focus on. Many of the supplies used during an operation are determined by how big a bird is. The essential equipment includes a bird identification guide, mist nets or other trapping devices, and banding pliers. A leg gauge, wing ruler, and a digital scale can also be useful.
Thanks to the work of the banding armies, ornithologists long ago established that migratory birds need intact habitats to survive. A few years ago, the Audubon Society published Survival by Degrees, a report showing that 64 per cent (389) of North American bird species risked extinction from climate change, industrial development and other factors. A gloomy report to a large degree, it said immediate, determined action could improve the odds for three quarters of the species in danger.
How does banding protect birds? Banders they record the location, date, species, gender, estimated age, and other features of those banded, then send that data to their national banding authority. To ensure the birds’ well-being, trained volunteers and researchers undertake the capture and banding. North America’s banding authorities work with the North American Banding Council, which develops banding materials and addresses safety regulations.
People who see or catch a banded bird report that information back to the lab, which keeps records of all reported encounters. Laboratory staffers manage more than seventy-seven million archived banding records and another 5 million bird encounter reports. Annually, the organization processes about 1.2 million banding records and 100,000 encounter reports.
Through banding research, scientists can learn a bird’s routines – where and how it spends its day, its migration patterns, what it eats, and the habitat it needs to feed and procreate. This information helps identify priority areas for conservation.
Banding data can reveal other trends in life span and population. If there is a change in the age of birds caught at a certain location, life expectancy may be getting shorter or longer. The number of birds captured may indicate whether populations are increasing or in decline. Data such as weight and wingspan can show health trends. Such insight can cue scientists to look for changes to birds’ food sources, predators, competitors, habitats, and other factors that affect their survival and reproduction. Sampling wild birds for Lyme Disease and Avian Influenza can help determine these diseases’ prevalence and risk, and which human and animal communities are at risk of exposure.
As we have seen, banding is by no means a recent practice. Two years ago, the US Geological Survey wrote a celebratory article about banding’s first century in North America. Birders are among the multitudes aware that most birds bring joy merely by their presence – from their bold colours and majestic songs to their grace as they flap or glide through the sky. But they contribute more than beauty. Many plants depend on hummingbirds and other species to pollinate them. Hawks and owls target rodents and other pests. Fruit- and grain-eating birds help spread the seeds of the plants they consume.
Bird researchers sometimes add additional markers to identify individuals in the field without the need to recapture them. Bands for large birds sometimes use colour and alphanumeric code combinations readable from a distance with binoculars or spotting scopes. The markers used depend on the type of bird, its behaviour and the information needed, and must avoid impeding movement. Banders follow strict protocols to virtually eliminate harm or hindrance to the species carrying them.
Although banders typically clip a small metal band with a unique number on the bird’s leg, larger birds may carry other markers. These include neck collars for geese and swans, readable from a distance with binoculars or a spotting scope. Wing markers on vultures, eagles, swans, ravens, crows, or herons are often visible while the birds are in flight or perched. Similarly, leg flags on shorebirds stick out from the upper leg with a code readable from a distance.
Regulation: As a scientific technique, banding requires expertise and skill usually gained through study and field experience. To participate in banding activities, you must apply for a permit. Professionals with banding permits include ornithologists, biologists, and wildlife technicians. Others are keen birders who just want to help.
Permits for banding in Canada come from the Canadian Bird Banding Office in Ottawa, which operates closely with America’s Bird Banding Laboratory. However, to get maximum value for this work banding programmes rely on the public to report their observations or recoveries of bird bands and other bird markers. The data these reports provide help scientists and researchers understand, monitor and conserve migratory birds. Banding data also track and publish species longevity records.
The presence or absence of birds can be signs of habitat loss, or stress patterns affecting ecosystems. Put another way, banding and its related technologies developed as tools of ornithology research into avian conservation science.
Banding data do indeed reveal vital developments: whether populations are increasing or in decline. Health data Illustrate trends and worries in respect to food sources, predation, competition, and habitat. Sampling wild birds for such bird-borne disorders as Lyme disease and avian influenza can provide a sense of these diseases’ prevalence, since the migration routes of infected species help identify which human and animal communities are at risk of exposure. In toxicology research, banding data can also show birds’ potential exposure to chemical contaminants, for example.
How to sum up? One of the great pleasures of birding is that it lures us into the natural world. Because it promotes practices that enable species better to survive, banding contributes to a healthier world.