Birds at risk in agricultural landscapes
A large proportion of land in southern Ontario is used for agriculture and these areas also provide essential habitat for several bird species whose populations are declining. Many questions persist about how these populations are affected by farming practices and what can be done to support bird conservation on farms without negatively affecting Ontario’s agricultural sector.
In 2016, we launched our birds at risk in agricultural landscapes program to learn more about declining grassland bird populations and work directly with the producers who create the nesting habitat these birds depend on. Our focal species are Bobolink and Eastern Meadowlark. Both species have experienced steep population declines and are listed as threatened in Ontario and Canada. They nest in hay fields, pastures, and other grassland-like landscapes. Our goal is to identify strategies to support grassland birds on farms and to engage producers in conservation science to address this conservation challenge.
Monitoring the impact of grassland bird stewardship projects (2017-2019): Various programs provide farmers with funding and incentives to implement best management practices (BMPs) that are intended to support grassland birds on farms (e.g., planting native grasses, installing fences to incorporate delayed grazing, delaying the hay harvest). Most of these programs do not include a monitoring component and there is little information available about the impact of these stewardship activities on the birds. We are working on a 2-year project to develop a monitoring scheme for stewardship projects and learn more about the impact of some of these BMPs on grassland birds.
Reproductive success in different land cover types and uses (2017-2019): In collaboration with Professor Erica Nol, graduate student Monica Fromberger, and others in the Nol lab at Trent University, we are studying Bobolink to learn about the environmental conditions that provide the best opportunities for reproductive success. By pooling existing data collected in pastures and hay fields, and monitoring nests during the 2-year project in conditions where data are lacking (e.g., restored grasslands and fallow fields), we will be able to model Bobolink nest survival across typical conditions. Our results should identify conditions associated with high nest survival, thus providing important information about the types and locations of future conservation efforts that could have the greatest positive impacts for nesting Bobolink.
Testing grazing strategies for Bobolink in pastures (2016-2018): In collaboration with the Ontario Soil and Crop Improvement Association and beef farmers in the Ottawa Valley, we investigated how rotational grazing can be modified to benefit the declining Bobolink population. In this 2-year project, we investigated if small Bobolink refuges that are left un-grazed during the nesting season (May through mid-July) are an effective conservation strategy. We collected data on cattle movements and Bobolink nesting success on 6 rotationally-grazed pastures. Small Bobolink refuges (~3 hectares each) provided areas where Bobolink nest success was substantially higher compared to when these areas were grazed during the nesting season in the other year of our experiment. We also found that sections of pasture grazed less intensively than normal can provide successful nesting areas for Bobolink, under certain conditions. Overall, our results suggest that pastures on rotationally-grazed beef cattle farms that are un-grazed until Bobolink finish breeding or grazed lightly soon after Bobolink begin nesting can provide areas that enable the birds to fledge young from nests. Future research on the ecological response of nesting Bobolink to grazing pressure and the timing of grazing is needed to clarify best management practices on farms that can benefit nesting Bobolink.
Tracking Bobolink movements using radio telemetry (2016): Hay fields are often cut before Bobolink nests fledge young. In 2016, we conducted a small pilot project to learn more about where adult Bobolink go and if they re-nest after their nests are destroyed by the hay harvest. To follow their movements, we tagged 5 birds with miniature radio-tracking devices. We tracked 3 Bobolink for more than 5 weeks; none of them re-nested. The other 2 birds disappeared from our study area shortly after the hay field they were nesting in was cut. This pilot project helped us understand the feasibility of a larger study to address our research questions.
Evaluating Bobolink and Eastern Meadowlark habitat use (2016): In collaboration with Katherine Robbins, a master’s student at Memorial University, we conducted point count surveys across 4 watersheds in southern Ontario to learn more about habitat use and landscape variables that influence the occurrence of Bobolink and Eastern Meadowlark. Results showed that the proportion of hay and pasture within 5 km of survey locations was a good predictor of Eastern Meadowlark habitat use.
Funding and support
Assistance for Monitoring the impact of grassland bird stewardship projects and Reproductive success in different land cover types and uses was provided by the Government of Ontario. BECO worked in partnership with the Ontario Soil and Crop Improvement Association on Testing grazing strategies for Bobolink in pastures. Funding was provided through the Species at Risk Partnerships on Agricultural Lands (SARPAL) program, an Environment and Climate Change Canada initiative. Additional funding from SARPAL supported Monitoring the impact of grassland bird stewardship projects in 2017. We thank the Ontario Trillium Foundation for supporting the launch of our birds at risk in agricultural landscapes program in 2016 and our project Tracking Bobolink movements using radio telemetry. Assistance for Evaluating Bobolink and Eastern Meadowlark habitat use was provided by the Government of Ontario and Mitacs. Additional support for our birds at risk in agricultural landscapes program was provided by Echo Foundation, the CICan Clean Tech Internships program, and donations. We are also grateful to Vortex Canada for loaning binoculars for conducting field research.