Studying Birds and Wildlands Ecology on the Great Plains

← Back to Featured News

It’s difficult to imagine a starker contrast to Vermont’s humid, hardwood forests than the dry, flat, spiny sweep of a shortgrass prairie. As Northeast Wilderness Trust’s (NEWT) Wildlands Ecologist, I spend most of my time studying the former—traversing rolling, rewilding forests of hemlock, maple, birch, and spruce, dotted with beaver ponds and bogs. But on a late-spring morning in early May, I found myself at work in an almost unrecognizable landscape: binoculars in hand, surrounded by sagebrush, yucca, and cholla on the banks of the Purgatoire River in southeastern Colorado.

Bison herd

Perhaps the term “river” is a generous description for that particular waterway. In the Northeast, it would likely be called a “creek” or “brook,” but on these arid plains, which receive only about 12 inches of rainfall annually, this modest waterway serves as a vital corridor and safe haven for plants, wildlife, and people. For three days this May, it also became a meeting place for rewilding advocates from across the United States to network and discuss bird conservation.

Hosted by Southern Plains Land Trust (SPLT) and the Bird Conservancy of the Rockies, with support from the Cornell Lab of Ornithology, the bird monitoring workshop brought together organizations with shared goals to compare approaches to avian conservation and practice field methods. Alongside NEWT and SPLT, other participating organizations included the Kentucky Natural Lands Trust based in Berea, KY, and Colorado West Land Trust, based in Grand Junction, CO.

SPLT’s executive director, Henry Pollock, facilitated the event and led us safari-style through two of their preserves: the new 500-acre Purgatoire River Preserve and their flagship property, the 43,000-acre Heartland Ranch. Bouncing along off-road across “America’s Serengeti,” we added grassland species to our birding checklists while discussing their larger roles in the shortgrass prairie ecosystem.

As our truck trundled along, Henry pointed out a Burrowing Owl, one of the many birds that depend on habitat created by prairie dogs. Prairie dogs are one of the Great Plains’ primary ecosystem engineers. Burrowing Owls nest in abandoned prairie dog mounds, and the rare Mountain Plover makes use of the bare ground that sprawls around their colonies. They are also the chief prey species for the Ferruginous Hawk.

We next came across flocks of Brown-Headed Cowbirds following in the dusty wake of bison, picking off insects stirred up by their activity. These relatively nondescript birds are often maligned in the Northeast due to a reproductive strategy called brood parasitism. Female cowbirds lay their eggs in the nests of other songbirds while the host mother is absent. The cowbird chick hatches several days earlier than the host species’ chicks, and because most songbird species cannot distinguish between their own chicks and the newly hatched cowbird, the host mother continues to feed it as if it were her own. The cowbird chick grows rapidly, outcompeting the host chicks, which often starve.

Scarlet Globemallow with ants

Variable-color Beardtongue

It is a brutal but innovative strategy, one whose evolutionary advantages are clear on the Plains. Brood parasitism permits the nomadic Brown-Headed Cowbirds to avoid the time and energy required to raise their own young so that they can follow bison herds, which offer a roving feast of insects.

As with many other behaviors in the natural world, brood parasitism may not be pretty, but it is a survival mechanism for a landscape profoundly changed by humans. When bison were nearly exterminated from the American West, at a time when most of the Northeast’s forests had been cleared, the cowbird’s range expanded dramatically. Today, these grassland birds occupy farm fields across the United States and follow cattle instead of native bison. Seeing the cowbird in its natural habitat gave me a newfound appreciation for this controversial species—and reminded me of the ecological ramifications of forest clearing and overhunting.

Perhaps the biggest takeaway of my trip boiled down to a greater appreciation for the birds I interact with daily. As I crouched among the sagebrush by the Purgatoire River, I heard an unmistakable song and caught a flash of red—a male Northern Cardinal in breeding plumage perched on a cottonwood tree. In the east, these are one of the most common backyard birds in cities and suburbs, but in the west, they are rare visitors. Many in the group had never seen one before and were left speechless. As I made my way back east, I told myself that I would refrain from taking for granted the cardinal’s early spring songs, and from vilifying cowbirds for their competition with Wood Thrushes and Eastern Phoebes. Instead, I’ll continue supporting NEWT’s work to rewild these species’ natural habitats, giving evolution the chance to play out on wildlands across my own home range.

Photography by Jason Mazurowski and Colin Woolley.