Grassland songbirds exhibit variable responses to the proximity and density of natural gas wells

Abstract

Cultivation of native prairie was likely the primary cause of historical declines of grassland bird populations in North America, but the increase in natural gas development may be exacerbating those declines through habitat loss and degradation. We quantified the abundance of grassland songbirds and vegetation structure across a gradient of natural gas well densities to determine the extent to which density and proximity of gas wells influence songbird abundance. In 2008 and 2009, we conducted 1,258 point counts on 105 native grassland parcels (1.6 km2/parcel) at varying distances from natural gas wells and with varying gas well densities (0–25 per 1.6 km2). We found that vegetation structure influenced bird abundance more strongly than natural gas well proximity or density for all but 1 species and that the response of grassland songbirds to natural gas well density and proximity varied among species and regions. Sprague's pipit (Anthus spragueii) and Baird's sparrow (Ammodramus bairdii) abundance was not influenced by natural gas well proximity or density. Grasshopper sparrow (Ammodramus savannarum), McCown's longspur (Rhynchophanes mccownii), and chestnut‐collared longspur (Calcarius ornatus) abundance was lower near gas wells, but both longspur species were also more abundant in areas with greater densities of gas wells. Horned lark (Eremophilus alpestris) abundance increased with well density in our northern study site. Savannah sparrow (Passerculus sandwichensis) abundance was higher near gas wells, but only in areas where well density was ≤9 wells/1.6 km2. We suggest that land managers and industry implement remediation activities that encourage vegetative re‐growth, thus reducing the potential interactive relationship between natural gas development and changes in vegetation structure. © 2014 The Wildlife Society.

Shallow gas development and grassland songbirds: The importance of perches

“…However, for most of our focal species it is unlikely that effects of wells on birds were caused by effects of wells on vegetation structure. Our results are inconsistent with those of Kalyn Bogard and Davis (), who detected greater effects of vegetation than shallow gas wells in another northern mixed‐grass prairie. We speculate that our results may have differed from Kalyn Bogard and Davis () because the abundance of exotic vegetation was lower in our study area.…”

“…Other studies reported a greater effect of well density on birds (Dale et al , Hamilton et al ), but this may have been due to differences in well footprint sizes and the amount of the surrounding area disturbed in each of the study locations. In our study area, the surface area affected by most shallow gas well pads was small, averaging 23.1 m 2 , and the largest measured footprint was 42.3 m 2 ; in contrast, Kalyn Bogard and Davis () studied effects of well sites where habitat was disturbed up to 276 m 2 in extent. Further, Dale et al () and Hamilton et al () conducted their research in the Wildlife Management Area of Canadian Forces Base Suffield (CFB Suffield), where almost all well heads were below‐ground and embedded within caissons, unlike shallow gas wells throughout most of Alberta.…”

“…Further research is required to determine whether shallow gas wells have smaller footprints on vegetation in grasslands without cattle, and thus our results are most relevant for other grazed prairies; nonetheless, because our results suggest that effects on almost all birds were not driven by vegetation structure, it seems probable that birds would respond similarly to shallow gas wells in grazed and ungrazed grasslands. However, vegetation structure can indirectly influence habitat selection by birds (Kalyn Bogard and Davis ) and other species.…”

Estimating offsets for avian displacement effects of anthropogenic impacts

“…). Yet other authors express displacement distance as a continuous variable without author interpretation of a specific distance (Kalyn Bogard and Davis ).…”

Impact of the Bakken/Three Forks unconventional oil and gas development on natural habitats in North Dakota

“…These concerns include water and air pollution, negative public health effects, noise and light pollution, increased seismic activity (via wastewater injection wells), increases in greenhouse gas emissions, and general quality of life issues (Bartik, Currie, Greenstone, & Knittel, ; Ellsworth, ; Jackson et al, ; Rosenberg, Phartiyal, Goldman, & Branscomb, ; Shonkoff, Hays, & Finkel, ). This energy trend has developed or modified substantial amounts of natural habitat across many parts of North America (Donnelly, Wilson, & Appiah, ; Drohan, Brittingham, Bishop, & Yoder, ; Jones, Pejchar, & Kiesecker, ; Moran et al, ; Trainor, McDonald, & Fargione, ), which likely has impacts on wildlife (Schneider, Stelfox, Boutin, & Wasel, ; McDonald, Fargione, Kiesecker, Miller, & Powell, ; Kalyn Bogard & Davis, ; Ludlow, Brigham, & Davis, ), ecosystem function (Jones & Pejchar, ), and ecosystem services (Allred et al, ; Jones et al, ; Moran et al, ).…”