Spring Migration
Every year, guided by an ancient, irresistible urge, millions of birds embark on extraordinary journeys across our planet. This remarkable migration is no simple choice; it is a deep-seated instinct woven into their very being, triggered by subtle shifts in daylight, temperature, and the scarcity of food. Driven by this primal calling, birds traverse vast continents and daunting oceans with astonishing precision and endurance.
Yet, these incredible voyagers face immense dangers on their epic journeys. Storms and turbulent weather test their endurance and climate change adds challenges as it increases unpredictability. Perhaps the gravest threats is the vast urban landscapes, gleaming skyscrapers, and sprawling airports that disrupt age-old pathways. Bright city lights disorient these weary travelers, and collisions with aircraft claim tens of thousands every year.
Birds undertake their remarkable migrations at varying altitudes and times of day, each finely tuned to their unique needs. Many songbirds, such as warblers and thrushes, travel under cover of darkness, soaring between 500 and 2,000 feet above the ground, using stars to navigate while reducing the risk of predators. Some larger birds like geese and cranes migrate during the day, flying in graceful formations at heights ranging from 3,000 to over 10,000 feet, taking advantage of thermal currents and favorable winds. Some species push these limits even further: Bar-headed Geese, for example, astoundingly traverse the Himalayas at altitudes exceeding 20,000 feet, demonstrating nature’s incredible adaptations for survival.
In North America, the grand spectacle of spring migration unfolds from late February through early June, as birds journey northward to their breeding grounds. Beginning in the southern states, early travelers like waterfowl and blackbirds set off in late winter, gradually joined by waves of songbirds in March and April. By late April and throughout May, migration reaches its peak, as vibrant warblers, orioles, hummingbirds, and tanagers flood forests and backyards across the US. By early June, most birds have settled into their northern territories, marking the close of an extraordinary, annual voyage—a timeless ritual announcing the arrival of spring.
As aviation wildlife managers, it’s important to stay up to date on the latest bird movements during this dynamic season. Although it’s great to see the return of our feathered friends, it can present significant wildlife hazards at and around airports. Some sites to keep in mind for monitoring include:
