Landbird monitoring in the Northern Colorado Plateau Network: 2015 field season

McLaren, Matthew; White, Chris

In 2015, the Bird Conservancy of the Rockies (Bird Conservancy), in cooperation with its partner, the National Park Service (NPS), completed its eleventh year of a habitat-based landbird monitoring program in park units of the Northern Colorado Plateau Network. This program is designed to provide rigorous population trend data for most diurnal, regularly occurring breeding landbird species throughout the network. This population information is useful for land managers and supports the National Park Service’s goal of long-term monitoring of biological indicators for network parks. In 2015, Bird Conservancy biologists surveyed 45 survey locations within 11 NPS units. Fifteen transects were located in each of the three habitats of interest: low-elevation riparian, pinyon-juniper, and sage shrubland. For the second year, each location was surveyed once instead of twice, as in all years before 2014. Because of the decrease in sampling effort, fewer species and individuals were recorded than in past years. Bird Conservancy staff do not expect the decrease in effort to significantly impact density estimates. However, a decrease in number of detections for a species in a given year due to decreased effort may impact the percent coefficient of variation for that species. In addition to the habitat-based surveys, four point counts and four area searches were conducted at Pipe Spring National Monument using a modified monitoring design. In 2015, all assigned habitat-based surveys were completed between May 11 and June 24. A total of 4,298 birds of 113 species were recorded. Observers detected 1,340 birds of 77 species in low-elevation riparian; 1,076 birds of 64 species in pinyon-juniper; and 1,882 birds of 81 species in sage shrubland habitat. Two species were recorded that had not been detected as part of this monitoring program in previous years. Common grackle was recorded at Curecanti National Recreation Area and Lewis’s woodpecker was recorded at Capitol Reef National Park. In addition to the habitat-based surveys, four point counts and four area searches were completed at Pipe Spring National Monument. Observers detected a total of 231 birds of 35 species during surveys at the monument. Fifty-one birds of 18 species were detected during point counts and 180 birds and 17 additional species during nocturnal and diurnal area searches. In 2015, cedar waxwing, western wood-pewee, and yellow-breasted chat, already designated as present in the monument, were detected for the first time during Bird Conservancy surveys. Prairie falcon, designated as unconfirmed, was also detected. Two species (orange-crowned warbler and yellow-headed blackbird) were detected for the first time on this project and are new species for the park. With each year of additional data, the Bird Conservancy is able to provide more precise estimates for more species in each habitat. This year, staff estimated densities of 63 species in at least one habitat. The data yielded robust density estimates (coefficient of variation <50%) for 38 species in at least one habitat. Observers recorded 45 bird species that are of conservation or management concern throughout the Northern Colorado Plateau Network and estimated densities for 28 of these species.

Landbird monitoring in the Northern Colorado Plateau Network: 2015 field season

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