Grassland songbird abundance is influenced more strongly by individual types of disturbances than cumulative disturbances associated with natural gas extraction

PLOS ONE RESEARCH ARTICLE Grassland songbird abundance is influenced more strongly by individual types of disturbances than cumulative disturbances associated with natural gas extraction Stephen K. Davis ID1,2☯*, Holly J. Kalyn Bogard1,2☯¤, David Anthony Kirk3‡, Lauren Moretto ID3‡, R. Mark Brigham2‡ a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Davis SK, Kalyn Bogard HJ, Kirk DA, Moretto L, Brigham RM (2023) Grassland songbird abundance is influenced more strongly by individual types of disturbances than cumulative disturbances associated with natural gas extraction. PLoS ONE 18(3): e0283224. https://doi. org/10.1371/journal.pone.0283224 Editor: Tunira Bhadauria, Feroze Gandhi Degree College, INDIA Received: November 9, 2022 Accepted: March 4, 2023 Published: March 17, 2023 Copyright: © 2023 Davis et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All data files are available from the Open Science Framework database. DOI 10.17605/OSF.IO/NRZSG. Funding: This project was supported by funding to HKB from student awards from: University of Regina (Department of Biology, Faculty of Graduate Studies and Research), Nature Regina, Nature Saskatchewan, and Saskatchewan Ministry of Environment (Fisheries & Wildlife Developmental Fund). HKB was supported by a MITACS 1 Environment and Climate Change Canada, Canadian Wildlife Service, Regina, Saskatchewan, Canada, 2 Department of Biology, University of Regina, Regina, Saskatchewan, Canada, 3 Aquila Conservation & Environment Consulting, Ottawa, Ontario, Canada ☯ These authors contributed equally to this work. ¤ Current address: University of Lethbridge, Lethbridge, Alberta, Canada ‡ DAK, LM and RMB also contributed equally to this work. * Abstract Grassland birds have undergone widespread global population declines due to loss and degradation of native grasslands. Activities associated with non-renewable energy derived from oil and natural gas extraction have substantially increased on grasslands. The cumulative disturbance generated by natural gas development creates a network of non-linear (e.g., bare ground and exotic plant species) and linear (e.g., roads, trails, pipelines) features that may degrade habitat quality for grassland species. We quantified grassland songbird abundance in two areas of southwestern Saskatchewan, Canada, to determine whether variation in abundance 1) depended on the type and amount of disturbance at two spatial extents, and 2) was more affected by the cumulative impacts of natural gas development than any single type of disturbance. We found that specific types of disturbances impacted the abundance of most species to varying degrees. The cover of different types of linear disturbance had the strongest effect on the most species. Natural gas disturbance within 450 m of point counts was more influential than disturbance within 200 m for nearly all species in both areas. Only Savannah sparrow (Passerculus sandwichensis) abundance was most strongly influenced by the cumulative amount of disturbance with abundance decreasing with increased disturbance. Overall, we detected few consistent patterns among species, or within species between our two study areas. Our results indicated that the impact of natural gas infrastructure can extend beyond the local influences associated with well sites and that relatively small amounts of disturbance (<2%) may impact grassland songbird abundance. We recommend that researchers use caution when studying well-density effects or combining individual types of disturbance without understanding the separate effects each type of disturbance has on the species or community of interest. Not doing so may lead to investing resources into management practices that do not have the greatest possible benefit for grassland songbirds. PLOS ONE | https://doi.org/10.1371/journal.pone.0283224 March 17, 2023 1 / 16 PLOS ONE Accelerate Saskatchewan award in partnership with Environment and Climate Change Canada. The project was also supported by funding to SKD by Agriculture and Agri-food Canada and Environment and Climate Change Canda’s Interdepartmental Recovery Fund. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Agriculture and Agri-Food Canada - https:// agriculture.canada.ca/en Environment and Climate Change Canada - https://www.canada.ca/en/ environment-climate-change.html Saskatchewan Ministry of Environment - https://www. saskatchewan.ca/government/governmentstructure/ministries/environment MITACS - https:// www.mitacs.ca/en/programs/accelerate Nature Regina – https://www.natureregina.ca/ Nature Saskatchewan - https://www.naturesask.ca/ University of Regina - https://www.uregina.ca/. Competing interests: The authors have declared that no competing interests exist. Grassland songbird abundance is influenced by natural gas disturbance Introduction The loss and degradation of grasslands through intensification of agricultural practices has led to widespread global declines in grassland bird populations [1–3]. The decline in grassland bird populations has continued despite a plateau, or even a decrease, in the global amount of grassland being converted to annual crops over the past 60 years [4, 5]. These population declines may be related, in part, to a substantial increase in industrial development over time, such as oil and gas extraction [6, 7]. Petroleum development has the potential to destroy and degrade the quality of remaining grasslands and therefore impact grassland bird populations. Copeland et al. [8] predicted that approximately 15% of grasslands in western North America could be impacted by oil and gas development. Most research on the biological effects of oil and gas development in grasslands has focused on well sites, specifically the type, density, and proximity of wells [9–12]. This research focus likely relates, in part, to the information requirements imposed by regulators regarding permitting, establishing mitigation guidelines, and reporting on drilling activity [13]. Negative impacts from the construction of well sites have been demonstrated for a number of taxonomic groups, including arthropods [14], amphibians [15], mammals [10, 16], and birds [9, 17]. Construction of well pads and other infrastructure destroys local grassland cover and may impact the broader landscape, having long-lasting effects on ecosystems [14, 18, 19]. For example, bare ground cover is greater and vegetation is shorter near natural gas wells, due in part to well construction activities and livestock congregating around well sites [11, 19, 20]. These changes in vegetation structure likely alter bird species composition and abundance in the lands (...truncated)