AUTHORS: Paulson Des Brisay*, Patricia Rosa, Christoph Ng, Nicola Koper – University of Manitoba
ABSTRACT: Landscape ecology is often criticized for describing species distribution patterns, but failing to determine the mechanisms that explain those patterns. In addition, landscape ecology tends to focus on species distributions and coarse measures of productivity, to accommodate the vast spatial scales over which sampling must occur; however, this further compromises our abilities to understand mechanisms behind landscape-scale patterns. We illustrate how landscape-scale manipulative experiments can allow us to overcome these problems. As anthropogenic noise becomes more prevalent across habitats, its impacts on wildlife remain difficult to assess. To disentangle effects of industrial noise from confounding factors (i.e. well presence, human activity, roads), we developed a high-fidelity solar-powered broadcasting system to reproduce sound from wells in sites without wells. We are comparing these “noisy” sites with sites with no wells, sites containing broadcasting equipment that is turned off, sites with real and active wells, and sites with real wells that are turned off (silent); we are evaluating impacts of these treatments on abundance, nesting success, clutch size, age structure, body condition, stress physiology, adult and fledgling survival, communication, and parental care at nests of grassland songbirds. We found negative effects of noise exposure per se on nesting success of Chestnut-collared Longspurs, Savannah Sparrows and Sprague’s Pipits, and on abundance of Chestnut-collared Longspurs and Vesper Sparrows. Female Chestnut-collared Longspurs, but not males, showed elevated corticosterone levels near noise playbacks, and noise explains some but not all negative effects of wells on parental care. However, noise did not explain variation in age structure or body size. The experimental design was essential and effective in allowing us to quantify the reasons for edge effects from wells on diverse fitness-related parameters. Our results demonstrate that both noise reduction and minimizing the footprint of above-ground infrastructure are necessary for mitigating effects of oil and gas development.
