Bird Studies Canada
Microphones versus Ears: Testing Songmeter Ability to Detect Marshbirds
Photo Credits: Ally Manthorne, Lucas Berrigan, Laura Achenbach
Wetlands provide key ecosystem functions and rich habitats for a diverse range of plants and animals. The Maritimes Marsh Monitoring Program (MMMP) aims to assess wetland-associated bird species, often not well-surveyed by other standard methods, and several of which are species at risk. However, surveying for these birds can be constrained by a short season, inclement weather, and numbers or availability of skilled observers. To supplement observer-collected field data, field-appropriate automated recording units (ARUs) with microphones can be deployed and left to “listen” for birds. ARUs are well-suited to monitoring nocturnal or other secretive species, and can increase geographical coverage and field capacity when field survey conditions are constrained. However, differences in performance between a recording device and a person (i.e. how far can ARU’s ‘hear”) are not thoroughly documented. Our study used paired human and ARU point counts to assess these detection differences and develop correction factors that can be applied to ARUs to improve their incorporation into long-term monitoring programs.
In 2018, Bird Studies Canada field technicians completed 742 paired ARU-human point counts in wetlands in multiple Canadian provinces (New Brunswick, Nova Scotia, Prince Edward Island, Ontario, Saskatchewan), and developed correction factors for 12 wetland-associated bird species. Fourteen of these paired point counts were completed in PEI.
Results from this study will allow us to use ARUs more effectively to monitor wetland-associated birds, providing a more complete and diverse picture of wetland species and habitat associations necessary for positive conservation outcomes.