Species · Utah · BBS 2025 Release · 1966–2024
Brown-headed Cowbird Population Trend in Utah
Brown-headed Cowbird in Utah has increased: up 39% on the route-weighted index since 1970.
+39%Since 1970
108Routes In State
56Years
Notable Brown-headed Cowbird Trends in Utah
No notable trend signals for Brown-headed Cowbird in Utah. See the full index history below.
Brown-headed Cowbird Population Forecast in Utah
If the recent trend holds, Brown-headed Cowbird in Utah is projected to rise about 10% by 2029 — from 2.4 in 2024 to a central estimate of 2.6 (95% range 0.00–9.0). A 5-year backtest shows a typical error of ±53.2%, with 100% of held-out values landing inside the 95% band.
+10%Change by 2029
2.6Projected 2029 index
0.00–9.095% range
±53.2%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 2.8 | 0.00 | 9.2 |
| 2026 | 2.8 | 0.00 | 9.2 |
| 2027 | 2.7 | 0.00 | 9.1 |
| 2028 | 2.7 | 0.00 | 9.1 |
| 2029 | 2.6 | 0.00 | 9.0 |
Brown-headed Cowbird Survey Routes in Utah
| Woodruff | 27 | 2024 | 2002 |
| Newcastle | 24 | 2022 | 1997 |
| Randolph | 20 | 2024 | 1992 |
| Bear River | 15 | 2023 | 1992 |
| Beck | 13 | 1987 | 1969 |
| Johnson Can | 13 | 2024 | 1988 |
| Fish Springs | 13 | 1987 | 1987 |
| Wellington 2 | 12 | 2011 | 2003 |
| Delta | 10 | 2024 | 1987 |
| Leamington | 10 | 2016 | 1992 |
| Kelton | 9 | 1995 | 1993 |
| Hardware Ranch | 9 | 2018 | 1998 |
| Wendover | 8 | 1997 | 1974 |
| Moquith Mtn | 8 | 2024 | 1987 |
| Promontory | 7 | 2024 | 1969 |
| Jensen | 7 | 2024 | 1992 |
| Hanna | 7 | 2024 | 1997 |
| Wellington | 7 | 2002 | 1998 |
| Wellington 3 | 6 | 2024 | 2012 |
| Goose Creek Mtn. | 6 | 2023 | 1997 |
| Pine Creek | 6 | 2023 | 1998 |
| Castleton | 5 | 1985 | 1970 |
| Bonanza | 5 | 2008 | 1992 |
| Lost Cr. Res | 5 | 2017 | 1995 |
| Hyrum | 4 | 1975 | 1975 |
Brown-headed Cowbird Population Trend in Other States
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Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.