Migration

Joe Meche is in his sixth year as editor of the Avalanche, the newsletter of the North Cascades Audubon Society, and a member of the board of directors.

One of nature’s most fascinating dramas is the migration of birds; the often-massive movements of birds between their breeding and wintering grounds. Migration is a term derived from the Latin migrare, which means to go from one place to another. Unlike avian dispersals, irruptions, or invasions, migration is seasonal, predictable, and repeated each year.

It has been estimated that as many as five billion land birds of over 200 species leave parts of North America every fall for Central and South America. Humans have been aware of the seasonal arrival and departure of birds since long before recorded history and misconceptions abounded as to exactly where birds went when they migrated. Some believed that swallows hibernated in the mud of ponds and lakes, or even flew to the moon!

Science has solved a lot of the riddles of migration, with increased understanding of the birds themselves, as well as climate and geography. Even though most of the mysteries of migration have been explained scientifically, the sight of a million birds in migration is still one of the most awe-inspiring spectacles that nature has to offer. Many people have become birdwatchers for life after viewing the large gatherings of migrants.

Whenever Roger Tory Peterson was asked how he became interested in birds, he always responded with his story of finding a yellow-shafted flicker on the ground while walking in the woods one day. As the story goes, he thought the bird was dead, but the flicker was merely resting and leaped into the air and flew away as he approached, much to the surprise of young Roger. So began his interest in birds.

Most people who watch birds have similar stories of how they became aware of birds and the vital part that birds play in our lives. I grew up in southwest Louisiana and my own interest in birds was kindled by large numbers of birds instead of an individual bird. The great migrations of birds, large and small, kindled an interest that continues to the present and often borders more on passion than mere interest.

Southwest Louisiana lies near the confluence of the Central and Mississippi Flyways and is one of the bird-busiest parts of the country, especially during the spring and fall migrations. My earliest bird-related memories are of foggy nights in late October when enormous flocks of geese began to arrive from their northern breeding grounds to winter in the rice fields and marshes that surrounded my hometown.

I can remember lying in bed in the middle of the night, while the rest of the family slept, listening to this strange, exotic sound and wondering why no one else was awake to hear all this wonderful noise. When my grandfather explained that the geese had come all the way from Canada to spend the winter with us, I was impressed; but I had to spend time at the local library to find out where Canada was!

At the library, I was fascinated as I scrutinized the atlas and marveled at the distance these birds had traveled. I was equally amazed that they could find their way to south Louisiana in the dark, much less in the fog.

The geese, mostly snow geese, began to arrive not long after the last rice harvest of the year and stayed until spring. We would hear them throughout the winter and see the incredible flocks lifting from the fields to escape the hunters or to move to another field or a night roosting area.

Wintertime trips to Grandma’s house were often punctuated with the sightings along the way of huge flocks in the fields or on the wing. The geese would grow noticeably restless as the weather warmed and the days grew longer, and then they’d begin to leave at some ancient signal that only they heard.

On one Sunday morning in particular, my family and I went to St. Michael’s for Mass, and I heard the geese as soon as I opened the car door. Enormous flocks like I had never seen before, or have seen since, were flying just overhead, heading north. The sky above the church was literally filled with geese. Their excited calls filled the air on that beautiful spring morning.

As was the custom at our church in the days before air conditioning, when the weather began to get warmer, the doors and windows were left open for ventilation. The entire service was barely audible for the cacophony overhead. Puzzled looks and knowing glances were exchanged throughout the service. The Monsignor even abbreviated his sermon since he couldn’t compete.

The spectacle of migration did not go unnoticed that day. Everyone leaving the church after Mass couldn’t help but look up as soon as they were outside. Geese continued flying over the church for the hour it took for the mass and were still streaming northward as we got in the car to go home. The number of individual birds was incomprehensible.

As geese and other waterfowl left for the north, the warblers and other passerine species began to arrive in our backyards and fields after their own journey northward from Mexico, and Central and South America. The larger birds were then replaced by brightly-colored bundles of energy, whose singing filled the air on spring mornings and into the summer. No matter how many volumes or accounts you read and study about avian migration, you can never fully comprehend the enormity of this phenomenon that is as reliable as night and day.

Centuries of observation and study of bird migration have attempted to understand this phenomenon; how birds can make these incredible journeys year after year, just like clockwork. While science can begin to unravel the basics, the sheer romance of bird movements cannot be overlooked.

Consider the tiny warblers making their way across the vast Gulf of Mexico against strong headwinds from unexpected storms; seabirds and shorebirds timing their arrivals to coincide with the spawning and egg-laying of fish and crabs; swallows returning to Capistrano right on schedule, every year; the movement of birds to herald the changing seasons.

Birds are among the most resilient members of the animal kingdom and the evolution of bird migration proves this point. Birds migrate to more favorable climates to raise their young where food supplies are plentiful. Some species, such as the Arctic tern, are known for their incredibly long journeys; they spend their entire lives traveling back and forth from the Arctic to the Antarctic. They nest during the Arctic summer and head south as early as August. They reach the Antarctic by November and after three months of summer in the Southern Hemisphere, they retrace their path northward.

Migratory birds also reflect environmental changes that occur throughout their expansive ranges. Bird counts, like the traditional Christmas Bird Count and the more recent International Migratory Bird Day count in May, reflect these changes by comparison of each year’s numbers to those of previous years.

Before humans became aware of the conservation of bird species, hunting decimated the populations of many species. In the case of the passenger pigeon, the species was hunted to extinction. Today, many organizations like the National Audubon Society work toward education and conservation so that future generations, too, can marvel at these winged wonders.

There are many opportunities to witness the spectacle of migration in this part of the country. From mid- to late-April, shorebirds migrating along the West Coast have been the springboard for birding festivals all along their route. These festivals serve as an introduction for many to migration and a celebration of the changing seasons, and promote the concept of habitat restoration and conservation for the birds’ sakes.

One of the largest gatherings of shorebirds on the West Coast takes place near the end of April at Bowerman Basin, west of Hoquiam on the Olympic Peninsula. The Grays Harbor Audubon Society sponsors a shorebird festival every year.

Large concentrations of birds closer to home are the gatherings of numerous sea ducks and gulls on the south end of Birch Bay in mid-April and the annual feeding frenzy of hundreds of Pacific, red-throated, and common Loons in the channel between Semiahmoo and White Rock, British Columbia. Large numbers of migrating shorebirds, Bonaparte’s gulls, waterfowl, and the occasional rare bird can be observed in the area around Marine Park and Drayton Harbor in Blaine.

On cold and rainy days, scan the bookshelves in your local bookstores and libraries and read about bird migration. While you might get to a point where you understand the concept, you still need to witness bits and pieces of this phenomenon to fully appreciate the awe-inspiring spectacle of migration.