Effects of grassland alteration from mowing and fire on bird activity at a Colorado airfield

• Main Authors: Kara A. Carragher, Rick M. Clawges, Rick L. Bunn, Helen K. Pigage, Jon C. Pigage
• Format: Article
• Language: English
• Published: Utah State University 2017-02-01
• Series: Human-Wildlife Interactions
• Subjects: bird–aircraft collisions; bird strikes; controlled burn; fi re management; grass management; habitat alteration; horned lark; human–wildlife conflicts; long grass; short-grass prairie; wildlife hazards
• Online Access: https://digitalcommons.usu.edu/hwi/vol6/iss2/12

Grass management has been used for many years at airports in an attempt to reduce numbers of birds and other wildlife and the collisions with aircraft associated with them. We evaluated the impacts of grassland alteration by mowing and fi re on the abundance, diversity, and frequency of birds using 1 control and 2 experimental grass plots from 2009 to 2010 on a U.S. Army airfield in Colorado located in short-grass prairie. Density of breeding birds was highest in the mowed plot. Numbers of birds observed in 34 surveys conducted during the non-breeding season in the burned (x = 41) and mowed (x = 24) plots were greater than in an unmanaged control (x = 7) plot. Bird species diversity in the nonbreeding season was greatest in the control plot. Horned larks (Eremophila alpestris) was the most frequently observed bird species and occurred in high numbers on the burned and mowed plots, possibly because of its preference for short vegetation and bare ground. This species is recognized as hazardous to aircraft in part because of its habit of forming large flocks in the nonbreeding season. All 3 study plots were dominated by grasses and forbs, with minimal shrub and cactus cover. Litter cover was greatest on the control plot, while the burned plot had the greatest coverage of bare ground. Results from this study are limited because the small size of the airfield precluded placement of multiple treatment plots. Additional study in larger airfields with multiple treatment plots would be required before management recommendations regarding the use of fi re and mowing can be made for airfields in areas with short-grass prairie.