Species · Utah · BBS 2025 Release · 1966–2024
Swainson's Thrush Population Trend in Utah
Swainson's Thrush in Utah has collapsed: down 92% on the route-weighted index since 1975.
-92%Since 1975
29Routes In State
43Years
Notable Swainson's Thrush Trends in Utah
long arc declinecomputed index
Swainson's Thrush has collapsed in Utah: down 91% on the route-weighted index since 1975.
Swainson's Thrush Population Forecast in Utah
If the recent trend holds, Swainson's Thrush in Utah is projected to fall about 100% by 2029 — from 0.19 in 2024 to a central estimate of 0.00 (95% range 0.00–3.5). A 5-year backtest shows a typical error of ±506.3%, with 100% of held-out values landing inside the 95% band.
-100%Change by 2029
0.00Projected 2029 index
0.00–3.595% range
±506.3%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.00 | 0.00 | 3.5 |
| 2026 | 0.00 | 0.00 | 3.5 |
| 2027 | 0.00 | 0.00 | 3.5 |
| 2028 | 0.00 | 0.00 | 3.5 |
| 2029 | 0.00 | 0.00 | 3.5 |
Swainson's Thrush Survey Routes in Utah
| Hyrum | 17 | 1979 | 1975 |
| Moon Lake 2 | 9 | 2023 | 2004 |
| Main Canyon | 9 | 2003 | 2003 |
| Soapstone | 6 | 2024 | 1992 |
| Moon Lake | 6 | 2002 | 1995 |
| Beck | 3 | 1970 | 1970 |
| Beaver | 3 | 1973 | 1973 |
| Gooseberry | 3 | 2024 | 1996 |
| Uintah Nf | 3 | 1994 | 1991 |
| Fish Lake Nf | 3 | 1996 | 1996 |
| Logan Canyon | 2 | 2019 | 1997 |
| Ferron | 2 | 2018 | 2009 |
| Hardware Ranch | 2 | 2023 | 1994 |
| Ant Flat-Ogden Can | 2 | 2023 | 1994 |
| Altonah | 1 | 2015 | 1975 |
| Grizzly Rdge | 1 | 2018 | 1987 |
| Lost Cr. Res | 1 | 2018 | 1995 |
| Oak City | 1 | 1996 | 1996 |
| Saleratus Cr | 1 | 1997 | 1997 |
| La Sal 2 | 1 | 2006 | 2006 |
| E. Bear Lake | 1 | 2021 | 2021 |
| Red Spur Mtn. | 1 | 2008 | 1997 |
| Navajo Lake | 1 | 2001 | 2001 |
| Hite | 1 | 1992 | 1992 |
| Skyline Driv | 1 | 2003 | 2003 |
Swainson's Thrush Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.