As the snow atop the Sky Islands begins to melt and the world awakens to the warmth of longer days, the skies above Arizona will be welcoming thousands of birds flying North for the summer. The annual spring bird migration through the borderlands region is a testament to the forces of nature.
The phenomenon of bird migration is one of the most fascinating aspects of the avian world. Each year, billions of birds undertake incredible journeys across continents, driven by instinct and the need to find suitable breeding grounds and food sources. Borderlands Wildlife Preserve (BWP) and the wildlife corridor it connects, with its diverse habitats ranging from high desert grasslands to lush riparian corridors to pine forests, provides one of the many essential rest stops for migratory birds traveling along the Pacific Flyway - one of the four main flyways in North America.
The National Audubon Society hosts a Bird Migration Explorer, an interactive map that shows real-time migration tracks and patterns across the American flyways, including species like these Turkey Vultures. You can check out the map here.
The Cornell Lab of Ornithology has created a website called BirdCast that shows real-time data on how many birds fly over a given state or county - every night during spring and fall migration. This may seem ridiculously impossible, but with advanced radar technology featuring dual polarization, along with decades of research, BirdCast is able to accurately count how many birds are flying, at what altitude, and in what direction. On April 1, 2023, over 47,000 birds flew over Santa Cruz County in one night!
Songbirds travel at night, partly to use stars for navigation and to avoid the strong gusts of daytime thermals - while larger soaring birds utilize them and migrate during the day as they soar along the warm, fluid pockets of air.
One of the highlights of birdwatching near Patagonia during the spring and fall migration is the incredible diversity of species that can be observed. As our already unique array of resident birds coincides with the seasonal travel of international birds, the opportunity to witness incredible species richness is all around us.
From tiny hummingbirds to towering raptors, the skies and landscapes come alive with new colors and sounds as traveling birds intermingle with resident species. Some birds are migrating a 'short' distance, like hummingbirds buzzing to southern Arizona from Mexico or southern Central America. Some raptors, like the Swainson's hawk, fly from as far south as Argentina. Cooper's hawks are considered partial migrants and travel much shorter lengths or are permanent residents, especially in areas like Patagonia, where the weather is relatively moderate all year round.
Among the many species that grace the skies during the spring migration, several stand out as particularly noteworthy. Many colorful, less common species, like the elegant trogon or painted bunting, maybe summering in southern Arizona and can be spotted. Others, like the Vermilion flycatcher, with its brilliant red plumage, are a common sight along the creeks and washes of Patagonia all year round.
The spring bird migration serves as a poignant reminder of the importance of conservation efforts in preserving critical habitats for migratory birds. Borderlands Restoration Network has installed and improved ponds at BWP to provide essential water sources and habitat for traveling birds, like the two turkey vultures seen resting at Jaguar Pond. Other organizations, such as Tucson Audubon Society and The Nature Conservancy, work to protect and restore critical migratory stopover sites, ensuring that future generations will be able to witness this awe-inspiring spectacle.
As the temperatures rise, the spring bird migration offers a glimpse into the remarkable journeys undertaken by over 350 species annually in the Americas. From the dazzling array of species to the breathtaking landscapes they traverse, this annual movement serves as a testament to the beauty and resilience of wildlife.