Landbird Population Trends in the Northern Colorado Plateau Network, 2025

Burrowing owl (Athene cunicularia) at Arches National Park.

Photo credit: Elizabeth Tymkiw

Why Landbird Monitoring Matters

Birds are key components in most ecosystems. They occur at various levels in the food web, providing an important service as they move energy throughout an ecosystem and a variety of habitats. They’re appealing to the public as they can be observed through both sight and sound. Because they can be sensitive to habitat change, birds are good indicators of ecosystem integrity.

Birds that rely on arid habitats, like those found in parks of the Northern Colorado Plateau Network (NCPN), are among the most vulnerable to population declines due to warming temperatures and increasing land use (Rosenberg and others 2016). The NCPN’s long-term bird monitoring program conducts regular check-ins of bird population status and trends in the parks. This allows managers to make timely decisions and quickly respond to any undesirable changes. It can also inform us about landbird status in more-impacted areas in the Intermountain West.

By-the-Numbers

• During 20 years of data collection (2005–2025), we conducted 17,443 point-count surveys across 11 NCPN parks and observed 168 unique species.
• During the 2025 field season, we conducted 666 point-count surveys and observed 106 unique species.
• With these data we generated 118 population-density trend estimations across three habitats for 61 species. Of these, 17% were significant, including eight negative trends and 12 positive trends.

What We’re Finding

As part of 20 years of data collection, 17,443 point-count surveys have been conducted in 11 NCPN parks, detecting 168 unique species. During the 2025 field season, we conducted 666 point-count surveys and observed 106 unique species, including two species new to the program: American avocet and green-winged teal.

When is the field season?

Field season for monitoring landbirds within their common habitats is limited to the bird breeding season, which begins approximately in early May and ends around early July (Daws, Beer, and Garman 2020). To learn more about monitoring guidelines, see the latest landbird protocol at Monitoring Protocols.

Using data from 2005–2025, 118 population-density trends were estimated across three habitats of interest: low-elevation riparian, pinyon-juniper, and sage shrubland. There were sufficient sample sizes to estimate the densities of 61 species in at least one of the three habitats surveyed. Twenty (17%) of the estimated density trends were significant (p-value < 0.05), including eight negative trends and 12 positive trends (Table 1).

Table 1. Significant density trends for landbird species in the NCPN, 2025, where “N/A” = not enough data available to estimate a trend; “–“ = no trend detected, ↑ = increasing trend, and ↓ = decreasing trend.

Common Name Scientific name	Low-elevation Riparian Habitat	Pinyon-juniper Habitat	Sagebrush Shrubland Habitat
Mourning Dove Zenaida macroura	↓	↓	–
White-throated Swift Aeronautes saxatalis	↓	↓	–
Hairy Woodpecker Leuconotopicus villosus	↑	N/A	N/A
Bushtit Psaltriparus minimus	↑	–	N/A
Bewick’s Wren Thryomanes bewickii	–	↓	N/A
Rock Wren Salpinctes obsoletus	–	–	↓
Mountain Bluebird Sialia currucoides	N/A	↓	–
American Robin Turdus migratorius	↑	–	–
Yellow Warbler Setophaga petechia	↑	N/A	–
Yellow-rumped Warbler Setophaga coronata	–	↑	–
Grace’s Warbler Setophaga graciae	N/A	–	↑
Yellow-breasted Chat Icteria virens	↑	N/A	N/A
Spotted Towhee Pipilo maculatus	–	↑	–
Vesper Sparrow Pooecetes gramineus	N/A	↑	–
Western Tanager Piranga ludoviciana	–	↑	↑
Lazuli Bunting Passerina amoena	–	↑	–
Western Meadowlark Sturnella neglecta	N/A	–	↓

First Time Observations

The observers had several detections of species in new locations. For example, in 2025, American Avocet (Recurvirostra americana) was observed in Curecanti National Recreation Area and Green-winged Teal (Anas crecca) was observed in Fossil Butte National Monument—both first detections for the monitoring program.

Several other species were detected in individual park units for the first time in this monitoring program. Common Nighthawk (Chordeiles minor) was detected in Bryce Canyon National Park; Lucy’s Warbler (Leiothlypis luciae) was detected in Colorado National Monument; Blue Grosbeak (Passerina caerulea) and House Wren (Troglodytes aedon) were detected in Curecanti National Recreation Area; Black Phoebe (Sayornis nigricans), Long-eared Owl (Asio otus), and House Wren in Dinosaur National Monument; and American Kestrel (Falco sparverius) in Zion National Park.

How We Monitor

NCPN monitors trends in breeding-bird species by habitat across 11 parks in the Northern Colorado Plateau. During each breeding season, our partner, the University of Delaware, surveys 15 transects in each of three habitats of interest (low-elevation riparian, pinyon-juniper, and sage shrubland). At Pipe Spring National Monument, four point-count surveys and an area search are conducted annually as part of a modified monitoring design.

What’s a “transect”?

A transect is a straight line that researchers follow, stopping at regular points to record observations about plants, soil, wildlife, or other natural features.

Where We Monitor

NCPN monitors landbirds in 11 network parks: Arches, Black Canyon of the Gunnison, Bryce Canyon, Canyonlands, Capitol Reef, and Zion national parks; Colorado, Dinosaur, Fossil Butte, and Natural Bridges national monuments; and Curecanti National Recreation Area (Figure 1). Monitoring is also conducted at Pipe Spring National Monument using a modified design.

Figure 1. NCPN parks where landbirds are monitored.

NPS

Extended description of map showing landbird monitoring parks in the NCPN, 2025

How We Can Use the Discoveries

Monitoring provides health check-ups for bird populations and the habitats they depend on. It allows scientists to identify and communicate changes in the status and trends of bird species and their environments to managers, who can then make timely, informed decisions to protect and conserve park resources. Data from this monitoring also contribute to park planning documents, such as Natural Resource Condition Assessments and State of the Park reports, and underscore the importance of protecting unimpaired national park landscapes for sustaining bird communities.

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Literature Cited

Daw, S., M. Beer, and S. L. Garman. 2020. Landbird Monitoring Protocol Narrative for Park Units in the Northern Colorado Plateau Network: Version 1.04. Natural Resource Report NPS/NCPN/NRR—2020/2119. National Park Service, Fort Collins, Colorado. https://irma.nps.gov/DataStore/Reference/Profile/2257072

Rosenberg, K.V., J.A. Kennedy, R. Dettmers, R.P. Ford, D. Reynolds, J.D. Alexander, C.J. Beardmore, P.J. Blancher, R.E. Bogart, G.S. Butcher, A.F. Camfield, A. Couturier, D.W. Demarest, W.E. Easton, J.J. Giocomo, R.H. Keller, A.E. Min, A.O. Panjabi, D.N. Pashley, T.D. Rich, J.M. Ruth, H. Stabins, J. Stanton, and T. Will. 2016. Partners in Flight Landbird Conservation Plan: 2016 Revision for Canada and Continental United States. Partners in Flight Science Committee.

Information in this article was summarized from Northern Colorado Plateau Network Landbird Monitoring Report 2025 by T. Schmidt, E. Tymkiw, and G. Shriver. Content was edited and formatted for the web by E. Rendleman.