Landbird Trends in Northern Colorado Plateau Parks, 2023

Birds sit at many levels of the food web and help move energy through ecosystems. Because they respond to changes in habitat, they are good indicators of ecosystem health, and data from the relatively natural habitats of the Northern Colorado Plateau Network parks provide a baseline to compare with more disturbed places.

How the monitoring works

The network, working with the University of Delaware, tracks breeding-bird trends by habitat rather than by park. Each breeding season, surveyors cover 15 transects in each of three habitats — low-elevation riparian (LR), pinyon-juniper (PJ) and sagebrush shrubland (SA) — across 11 parks, and Pipe Spring National Monument is surveyed with a modified design of point counts and area searches.

Monitoring covers 12 parks: Arches, Black Canyon of the Gunnison, Bryce Canyon, Canyonlands, Capitol Reef and Zion national parks; Colorado, Dinosaur, Fossil Butte, Natural Bridges and Pipe Spring national monuments; and Curecanti National Recreation Area.

Northern Colorado Plateau Network parks where landbirds are monitored. National Park Service figure.

Long-term trends

Over 18 years, surveyors completed 16,159 point counts in the 11 main parks and detected 176 species. Using data from 2005 to 2023, the network estimated 118 population-density trends for 61 species across the three habitats. Fourteen were statistically significant: eight rising and six falling.

Significant landbird population trends by habitat, 2023. National Park Service figure.

↑ significant increase; ↓ significant decrease; – no significant trend; NA not estimated.

The 2023 season

Surveyors made 599 point counts and recorded 4,936 birds of 118 species. Three species were new to the program: a northern pygmy owl at Canyonlands National Park, and a sandhill crane and a California gull at Fossil Butte National Monument.

Several birds were also recorded for the first time at particular parks:

• cedar waxwing and peregrine falcon at Arches;
• Townsend's solitaire at Canyonlands;
• Cordilleran flycatcher at Colorado National Monument;
• Savannah sparrow at Curecanti;
• osprey at Dinosaur;
• Virginia's warbler and Brewer's blackbird at Pipe Spring, where 132 birds of 34 species were counted — too few to estimate trends.

How the data are used

Park managers need to know which species are present in order to decide which to manage for. The data also feed planning documents such as Natural Resource Condition Assessments and State of the Park reports, and show the value of unimpaired park landscapes to bird communities.

Sources

• National Park Service, Northern Colorado Plateau Inventory and Monitoring Network: "Landbird Population Trends in the Northern Colorado Plateau Network, 2023," summarizing S.G. Roberts, E.L. Tymkiw, Z.S. Ladin and W.G. Shriver, Landbird monitoring in the Northern Colorado Plateau Network: 2023 field season, Science Report NPS/SR—2024/138.