Background: As with many species of birds that nest in North American grasslands, Grasshopper Sparrow numbers are declining—the population in Ontario decreased by about 72% between 1970 and 2019. Although the governments of Canada and Ontario list the Grasshopper Sparrow (Eastern subspecies) as Special Concern, there are many knowledge gaps and few conservation efforts focused on the species. In 2022, we began a Grasshopper Sparrow research project based in Grey County to learn more about this under-studied species and engage the agricultural community in stewardship.
Project work: To increase knowledge about the distribution, abundance, and habitat associations of Grasshopper Sparrows and to locate study sites for field research, we surveyed 495 acres of hayfield, pasture, and fallow grassland on 10 farms in Grey County and the surrounding area in late spring. We visited each farm twice to conduct transect surveys, recording all grassland bird species at risk detected.
To learn more about Grasshopper Sparrow nesting ecology, the impacts of farm management, and the effectiveness of stewardship actions, we conducted intensive field research on 8 farms in Grey County. On 7 of the 8 farms, conservation actions were implemented to support Grasshopper Sparrow nest success (e.g., delayed haying, avoidance of nesting areas). We monitored 31 Grasshopper Sparrow territories to determine if males were paired, the timing of nesting, if pairs nested successfully, if they raised multiple broods, and the impact of farm management and conservation actions. We used behavioural observations and nest monitoring to assess breeding status, visiting each Grasshopper Sparrow territory about twice per week for the duration of the nesting season.
We also collected vegetation data, including vegetation height, density, composition, and dominant species in fields occupied by nesting Grasshopper Sparrows on 5 of the 8 farms. Vegetation data were collected before and after disturbance (i.e., grazing, clipping) on 3 of the 5 farms. No disturbance occurred to fields occupied by nesting Grasshopper Sparrows on the other 2 farms.
Conservation implications: On each of the 8 farms where we monitored Grasshopper Sparrows throughout the nesting season, we provided farmers with information on territory and nest locations, nesting status, and guidance regarding conservation actions they could implement to increase nest success. Conservation actions implemented on farms included delayed haying and grazing, excluding cattle from or mowing around areas with active nests, and modifying grazing rotations to minimize disturbance to nesting birds. In fall of 2022, we will disseminate individualized reports to farmers that summarize the impact of stewardship actions and include site-specific recommendations to provide long-term conservation benefits to Grasshopper Sparrows. Information given to farmers during the field season and in individualized reports is intended to provide practical guidance that farmers can use to make management decisions for target areas to minimize impacts on Grasshopper Sparrows (and other grassland birds), thereby increasing the chances of these birds successfully raising young.
Project date: 2022
Funding: Support for this project was provided by Environment and Climate Change Canada’s Habitat Stewardship Program for Species at Risk, The McLean Foundation, Hodgson Family Foundation, K.M. Hunter Charitable Foundation, S. M. Blair Family Foundation, Jackman Foundation, Colleges and Institutes Canada’s Clean Tech Internship program, Canada Summer Jobs, and individual donors.
This project was undertaken with the financial support of the Government of Canada.
Ce projet a été réalisé avec l’appui financier du gouvernement du Canada.
We used behavioural observations to assess the breeding status of Grasshopper Sparrows and the impact of agricultural activities on nesting across 8 farms in Grey County.
Photo: Misha McCaughan
Rotational grazing in this pasture provided Grasshopper Sparrows opportunities to nest successfully. One field was left ungrazed until late in the nesting season. Two other fields were grazed in late May and early June, then not grazed again for about 8 weeks, providing a long enough rest period for birds to raise young between grazing occasions.
Photo: Zoé Lebrun-Southcott
Grasshopper Sparrow nests are built directly on the ground, hidden by vegetation, frequently domed with a partial roof. Females alone incubate the eggs.
Photo: Zoé Lebrun-Southcott