Status and trends of landbird populations in the Northern Colorado Plateau Network: 2023 field season
Roberts S, Tymkiw E, Ladin ZS, Shriver G. 2024. Status and trends of landbird populations in the Northern Colorado Plateau Network: 2023 field season. Science Report. NPS/SR—2024/138. National Park Service. Fort Collins, Colorado. https://doi.org/10.36967/2304411
In 2023, the University of Delaware, in cooperation with the National Park Service (NPS), completed the eighteenth year of a habitat-based landbird monitoring program in park units of the Northern Colorado Plateau Network (NCPN). 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 NPS’s goal of long-term monitoring of biological indicators for network parks. University biologists surveyed 42 out of 45 survey locations within 11 NPS units in 2023. Fifteen transects were located in each of the three habitats of interest: low-elevation riparian, pinyon-juniper, and sagebrush shrubland. Each location was surveyed once. In addition to the habitat-based surveys, four point-count surveys and an area search were conducted at Pipe Spring National Monument using a modified monitoring design. Over 18 years of data collection, 16,159 point-count surveys were conducted in 11 NCPN units, detecting 176 unique species. During the 2023 field season, 599 point-count surveys were conducted, detecting 118 unique species. In addition, since 2009, a modified protocol that includes four point counts and an area search has been conducted at Pipe Spring National Monument. Using data from 2005 to 2023, 118 population-density trends were estimated across the three habitats. Fourteen of the estimated density trends were significant (p-value <0.05). Six negative trends were observed: mourning dove (Zenaida macroura) and white-throated swift (Aeronautes saxatalis) in low-elevation riparian, and mourning dove, white-throated swift, Bewick’s wren (Thryomanes bewickii), and mountain bluebird (Sialia currucoides) in pinyon-juniper areas. Additionally, eight positive trends were found: hairy woodpecker (Leuconotopicus villosus) in low-elevation riparian; lazuli bunting (Passerina amoena), yellow-rumped warbler (Setophaga coronata), vesper sparrow (Pooecetes gramineus), and western tanager (Piranga ludoviciana) in pinyon-juniper habitats; and western tanager, Grace’s warbler (Setophaga graciae) and lark sparrow (Chondestes grammacus) in sagebrush shrubland. There were sufficient sample sizes to estimate the densities of 61 species in at least one of the three habitats surveyed.
- Type
- Published Report
- Authors
- Roberts, Samuel; Tymkiw, Elizabeth; Ladin, Zachary; Shriver, Greg
- Date of Issue
- 2024-06
- Publisher
- National Park Service
- DOI
- 10.36967/2304411
- Units
- ARCH , BLCA , BRCA , CANY , CARE , COLM , CURE , DINO , FOBU , NABR , NCPN , NRSS , PISP , ZION
- Keywords
- Animal Studies, bird population trends, Birds, distance sampling, inventory and monitoring, low-elevation riparian, Monitoring, National Park Service, NCPN Landbird Monitoring, Northern Colorado Plateau Network, pinyon-juniper, sagebrush shrubland
- Subjects
- Ecological Framework: Biological Integrity | Focal Species or Communities | Birds , NPS.gov Subject Site: Birds & Birding