Audubon Surveys Bobolinks to Time Safe Hay Mowing
Audubon staff and volunteers in New York survey Bobolink nesting to determine when chicks have fledged, guiding farmers on safe mowing times to prevent
Staff and volunteers with Audubon New York are conducting grassland bird surveys at Buttercup Farm Audubon Sanctuary to prevent chick mortality. Their research directly informs when farmers can safely mow their fields without harming ground-nesting Bobolinks.
Hailey Faurot, an Educator Naturalist Intern with Audubon, helps lead the surveys. The team tracks Bobolinks, American Kestrels, and Eastern Meadowlarks from late May through August, focusing on the high-priority Bobolink. They have not observed Eastern Meadowlarks at the site this year, believing the grassland patches are insufficient.
The Threat from Mowing
Bobolinks build their nests directly on the ground in grassy fields. This makes their young highly vulnerable to large haying equipment. The core goal of the survey is to pinpoint when most nestlings have successfully fledged, or left the nest. Mowing after this point avoids causing bird stress and death.
"We learn when the Bobolinks have completed their rearing and when fledglings are able to fly," Faurot reports. This critical timing data is then shared with nearby landowners through publications and workshops.
Conducting the Bird Surveys
The sanctuary is divided into field groups for monitoring. Faurot's team covered three fields with five distinct survey points. Their method involves sitting silently for two minutes to let birds acclimate, then observing and listening for five minutes with binoculars.
At each point, every bird seen is recorded, with notes on its sex, approximate age, and other useful details. Land steward Dave Decker analyzes the compiled data at the season's end. These results guide habitat management at Buttercup and inform Audubon's advice to farmers and grassland owners.
Monitoring Field Vegetation
In addition to counting birds, the team monitors the plant life in the fields. Bobolinks prefer to nest in areas dominated by grasses over non-grass plants, known as forbs. The vegetation survey assesses this balance.
Using a tape to transect a field, observations are recorded within 12-inch square plots. This provides a strong sample of field conditions. The team also involved high school students from the No Child Left Inside organization, adding a science communication and community outreach element to the work.
On one of the final survey days, the team observed a promising sign: many juvenile Bobolinks perched together on tall grass blades. This indicated successful fledging and the completion of the breeding cycle. Faurot noted the absence of adult females in the main flock, humorously comparing the scene to "Bobolink summer camp" where mothers get a break after rearing their broods.
Faurot reflects that the work, while addressing the steep declines faced by Bobolinks and other grassland birds, highlights positive local conservation actions. Monitoring these populations contributes directly to their survival.
