Monitoring as a Means to Focus Research and Conservation - The Grassland Bird Monitoring Example
|Authors:||Brenda Dale, Michael Norton, Constance Downes, Brian Collins|
|Type:||General Technical Report|
|Station:||Pacific Southwest Research Station|
|Source:||In: Ralph, C. John; Rich, Terrell D., editors 2005. Bird Conservation Implementation and Integration in the Americas: Proceedings of the Third International Partners in Flight Conference. 2002 March 20-24; Asilomar, California, Volume 1 Gen. Tech. Rep. PSW-GTR-191. Albany, CA: U.S. Dept. of Agriculture, Forest Service, Pacific Southwest Research Station: p. 485-495|
AbstractOne recommendation of the Canadian Landbird Monitoring Strategy of Partners in Flight-Canada is to improve monitoring capability for rapidly declining grassland birds. In Canada, we lack statistical power for many grassland species because they are detected in small numbers, on a low number of routes, or show high year-to-year variability. In developing a Grassland Bird Monitoring program we focused our efforts on improving coverage of “at risk” and endemic grassland species by intensifying coverage of Breeding Bird Survey type routes within degree blocks where grassland is still relatively common. To evaluate the Grassland Bird Monitoring data, collected from 1996 through 2000, we compared values to those collected by the Breeding Bird Survey during the same time period. Adding random routes inside the core of grassland bird distribution had a number of positive results. New routes averaged 48 percent grassland coverage and 36 percent crop coverage while Breeding Bird Survey routes averaged 70 percent cropland. The number of routes available for analysis increased by more than 25 percent for eight of ten primary and two of ten secondary target grassland birds. The number of birds per route was higher for eight of ten primary species. We collected simple habitat information and determined that, for many of the species, only a small proportion of available grassland was used (Baird’s Sparrow [Ammodramus bairdii], 36 percent; McCown’s Longspur [Calcarius mccownii], 8.5 percent). A substantial proportion of detections for some bird species were in crop where successful reproduction is unlikely. For McCown’s Longspur the proportion varied from 19.4 to 41.8 percent during the five-year study. Trends from Grassland Bird Monitoring routes were more positive than Breeding Bird Survey trends for the same time period for 12 of 18 species. For four of ten primary target species (Sprague’s Pipit [Anthus spragueii], Baird’s Sparrow, Lark Bunting [Calamospiza melanocorys], and McCown’s Longspur) declines on Grassland Bird Monitoring routes were more dramatic than those from Breeding Bird Survey. This may indicate that habitat quality, as well as quantity, is an issue or that additional productivity or wintering ground issues are affecting populations of these species. The Grassland Bird Monitoring pilot study demonstrates the program’s present and future utility for improving monitoring power while focusing conservation and research.
- Bird Conservation Implementation and Integration in the Americas: Proceedings of the Third International Partners in Flight Conference. 2002 March 20-24; Asilomar, California, Volume 1 and 2