Species · Montana · BBS 2025 Release · 1966–2024
Black Tern Population Trend in Montana
Black Tern in Montana has fallen sharply: down 71% on the route-weighted index since 1971.
-71%Since 1971
12Routes In State
35Years
Notable Black Tern Trends in Montana
long arc declinecomputed index
Black Tern has fallen sharply in Montana: down 71% on the route-weighted index since 1971.
Black Tern Population Forecast in Montana
If the recent trend holds, Black Tern in Montana is projected to stay roughly flat through 2028, near 0.00 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±71.3%, with 100% of held-out values landing inside the 95% band.
n/aChange by 2028
0.00Projected 2028 index
0.00–0.4195% range
±71.3%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2024 | 0.02 | 0.00 | 0.43 |
| 2025 | 0.01 | 0.00 | 0.42 |
| 2026 | 0.01 | 0.00 | 0.42 |
| 2027 | 0.01 | 0.00 | 0.42 |
| 2028 | 0.00 | 0.00 | 0.41 |
Black Tern Survey Routes in Montana
| Kalispell | 7 | 2018 | 1970 |
| St Mary | 3 | 2002 | 2002 |
| Great Falls | 3 | 2002 | 1978 |
| Sunburst | 2 | 1968 | 1968 |
| Malta | 2 | 1989 | 1979 |
| Pablo Res. | 2 | 2017 | 2009 |
| Glen | 2 | 1978 | 1978 |
| Westby | 2 | 2023 | 2023 |
| Harlem | 1 | 1993 | 1980 |
| Arlee | 1 | 1984 | 1968 |
| Augusta | 1 | 1985 | 1984 |
| Ester Lake | 1 | 2019 | 2019 |
Black Tern Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.