Individual study: Effect on breeding (non-game) birds of two sagebrush Artemesia control methods, central Utah, USA
Castrale J.S. (1983) Effects of two sagebrush control methods for nongame birds. Journal of Wildlife Management, 46, 945-952
Management of sagebrush Artemesia spp. in sagebrush-dominated landscapes may be undertaken to provide a mosaic of successional stages and to improve forage for wild ungulates or domestic livestock. A study was undertaken in central Utah (western USA) to assess the effects on breeding (non-game) bird populations in sagebrush Artemesia habitat chained and burned 3-4 years earlier.
Breeding bird densities were estimated by field surveys at sites 3-4 years after sagebrush Artemisia spp. control (one chained, one burned). Chaining consists of dragging a large chain across the landscape to knock down vegetation, aimed at allowing new growth to emerge.
Bird densities were compared with one site that had not received any recent Artemesia control (a 17-year-old ploughed site).
Bird response varied from species to species. Total densities and species richness were similar among sites (81-109 territories/kmÂ² of 4-6 species). However, the burned site had 50-86% fewer Brewer's sparrow Spizella breweri (a sagebrush specialist declining in parts of its range) territories than the chained and 17-year-old ploughed sites. Sage thrasher Oreoscoptes montanus (another sagebrush specialist) was only recorded where patches of the largest shrubs were present (dense sagebrush stands are required for nesting). Vesper sparrow Pooecetes gramineus and western meadowlark Sturnella neglecta (both species characteristic of open grassy areas) appeared unaffected by sagebrush control. Horned lark Eremophila alpestris densities were greater (1.8-2.8 fold) on the recently treated (sparsely vegetated) sites compared to the more vegetated, unmanaged site.
Note: If using or referring to this published study please read and quote the original paper, the abstract can be viewed at: http://www.jstor.org/pss/3808227