Squadrons From The North

Like a slithering gray wall, dark, foreboding clouds creep over Ottawa's southeastern horizon. Within moments, the colourless sky looms overhead. In the distance, the approaching trample of rain drops gradually increases its volume. I wait by the river and watch as tiny droplets trickle down my shoulder. The serenity breaks with a bolting flash and thunderous roar. At the mercy of the elements, I become drenched.

I stand my ground while flocks of peep scurry at my feet. Hundreds of Semipalmated Sandpipers, mixed with a sprinkle of other species, run across the sand bar, oblivious to my presence. The chirping and peeping of waders rises above the roaring downpour. The occasional burp of a Pectoral Sandpiper punctuates the orchestration. Through the soupy rain, small flocks swirl low off the river, and over the sandbar, like swarms of starving locusts flying into a crop. The tired migrants seek refuge on the muddy sanctuary, but waste no time in refuelling, as they frantically probe the mud for tasty invertebrate morsels. The feeding frenzy dwindles as the storm passes. Rows of sleeping sandpipers form along the foamy shoreline. With surprising ease, I approach the reposing migrants. Their bills tucked neatly into their scapulars, each bird periodically opens its eyes, then back to slumber, seemingly unconcerned with my crawl.

All seems calm until a piercing alarm echos through the flock. Their heads rise up and alert. Then, with perilous immediacy, the flock takes flight over the river in a tight group, zigzagging through the air like aerobatic precision pilots, manoeuvring from a stealthy and invisible predator.

For one unsuspecting Semipalmated Plover, it is too late. Down the sandbar, I notice a retreating Peregrine Falcon, plucking its prey as it flies toward a perch, high in the branches of a leafless cottonwood.

Shorebird migration provides countless episodes of wildlife drama. Huge concentrations gather at staging grounds, their numbers sometimes staggering. At Mary's Point, New Brunswick, hundreds of thousands of Semipalmated Sandpipers gather in late summer to feast on the abundant Mud Shrimp that flourish in the exposed intertidal mudflats. The concentrations of swirling flocks are among the biggest in the Americas. Waiting in the shadows are predators like Merlins, Sharp-shinned Hawks and Peregrines. The life-and-death struggle that ensues is exciting or tragic, depending on your perspective. Similar, but smaller, events like these occur across the continent in Spring and Fall.

Keen-eyed birders lucky enough to live near important staging areas wait for weather systems and storm fronts to disrupt bird migration. The resulting fallout often proves to be the best birding of the year. Scanning through flocks of different species reveals the occasional misdirected vagrant, perhaps a Buff-breasted Sandpiper, or a European stint.

Fortunately, North American shorebirds are easy to observe. They feed out in the open, and at all times of day. As a bonus, they are confiding and easily approached. But, they also provide an extreme birding challenge. Some have a tendency to wander out of their normal range. And, many plumages suffer from featureless characters, especially in winter. This makes even the most determined birder scratch their noggin. But the challenge is intoxicating, causing the devoted naturalist to spend hours in the rain, studying the subtle differences of bill shape and toe webbing. Just remember to step back and marvel as they poke their beaks into the gooey mud.