Exploring Impacts of Regenerative Grazing Practices on Grassland Birds
Managed hayfields and pasturelands are valuable nesting habitat for grassland birds, which are among the most imperiled group of birds in North America. However, these working landscapes have deteriorated in their ability to support grassland birds due to more frequent and early hay cuttings and intense grazing in recent decades. Through our grassland biodiversity surveys, VWL has been exploring how the management of our region’s grasslands influence bird communities since 2011. While this research has provided important insights into relationships between local conservation practices and grassland bird abundance, we have not had opportunities to explore how specific practices, such as grazing or haying, influence reproductive success. However, knowing this information is important for identifying factors that either impede or promote population growth.
In collaboration with American Farmland Trust’s Sustainable Grazing Project, VWL researchers are working with a small group of cattle producers to initiate a new study that will provide insights into how regenerative grazing practices influence nesting success of grassland birds, like Eastern Meadowlarks and Grasshopper Sparrows. In this pilot experiment, scientists will measure and compare the nesting success of birds occupying fields that are actively grazed, hayed and stockpiled (set aside for winter grazing). Since the timing and approach of management activities is the most crucial factor for the successful breeding of grassland birds, it is our goal to identify local farming practices that not only work for producers but also contribute to the recovery of grassland birds.
Update, December 30, 2020: In 2020, our field team used a combination of behavioral observations and nest searching to measure the reproductive success of grassland birds nesting in pastures under regenerative grazing management. Our team monitored a total of 65 nests and 107 territories throughout the breeding season. We found that 48% of birds were successful in fledging young, with the highest success rate occurring in pastures that were grazed early. These preliminary results suggest that grazing pastures early and stockpiling for winter may be the most beneficial to nesting grassland birds
We found that the majority of grassland birds nested between the period of May 11th and June 28th. The timing of breeding activity is not only determined by internal biological factors but by local factors such as food availability and temperature which can vary season to season.
As more data is needed to capture seasonal variability and make robust conclusions, these preliminary findings are still notable. Determining when grassland birds finish breeding in pastures can help us to refine management strategies and minimize the negative effects of grazing and haying practices.
Stay tuned for future updates as we continue this project in spring 2021!
Amy Johnson – Virginia Working Landscapes
Jacob Gilley – American Farmland Trust
Project Timeline & Status:
Field work began Spring 2020 – Ongoing
This project is supported by The Band Foundation
Interested in our nesting ecology research? Click here for information on our research with Smithsonian’s Movement of Life Initiative using drone technology to assist with nest searching.