A Banding "Grand Slam" at the Bent of the River Audubon Center

The Bent of the River Audubon Center is no sports stadium, but it was nevertheless the site of an exciting “grand slam” this year—just with birds, not baseballs. 

During a single session, their licensed bird bander captured and banded each of their four focal species: a Prairie Warbler, a Field Sparrow, a Blue-winged Warbler, and an Indigo Bunting. 

This is the first time they’ve recorded all four in one banding session, a win staff attribute to recent intensive management of the center’s Cedar Fields.

In the fall, their team removed trees, saplings, and invasive plants from the area to create healthy early successional habitat for their focal species to nest in come spring. This management work was informed by the center’s regular banding and territory mapping, which tell their staff which species are using the early successional habitat, and how.

It was more intensive management than they’d performed in several years, and the results were nearly instantaneous.

The number of Prairie Warbler territories in the managed fields, for example, jumped from 1 to 5—a 400 per cent increase that only adds to the proof shown by a successful season of bird banding!

Each focal species bird banded at the center was released with a random combination of colored “auxiliary” bands, in addition to the standard USGS aluminum band. The colored bands help staff identify individual birds in the field without having to capture them again—including the record-breaking 12-year-old Blue-winged Warbler that was re-sighted in 2025 and again this spring.

As summer winds down into autumn, staff will use this data to inform their early successional habitat plans for the season. 

You can add to this data by keeping an eye out for color-banded birds at the Bent and reporting any sightings—and the specific arrangements and colors of the bands—to bentoftheriver@audubon.org! 

Please note: Bird banding is a highly regulated scientific process strictly conducted by permitted professionals and Audubon’s biologists.