Species · Iowa · BBS 2025 Release · 1966–2024
Henslow's Sparrow Population Trend in Iowa
Henslow's Sparrow in Iowa has surged: up 293% on the route-weighted index since 1978.
+293%Since 1978
16Routes In State
27Years
Notable Henslow's Sparrow Trends in Iowa
long arc increasecomputed index
Henslow's Sparrow has surged in Iowa: up 293% on the route-weighted index since 1978.
Henslow's Sparrow Population Forecast in Iowa
If the recent trend holds, Henslow's Sparrow in Iowa is projected to rise about 173% by 2029 — from 0.09 in 2024 to a central estimate of 0.25 (95% range 0.00–0.62). A 5-year backtest shows a typical error of ±308.4%, with 100% of held-out values landing inside the 95% band.
+173%Change by 2029
0.25Projected 2029 index
0.00–0.6295% range
±308.4%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.24 | 0.00 | 0.61 |
| 2026 | 0.24 | 0.00 | 0.61 |
| 2027 | 0.24 | 0.00 | 0.62 |
| 2028 | 0.24 | 0.00 | 0.62 |
| 2029 | 0.25 | 0.00 | 0.62 |
Henslow's Sparrow Survey Routes in Iowa
| Williamsburg | 4 | 2008 | 2003 |
| Bedford | 2 | 2013 | 2001 |
| West Liberty | 2 | 2017 | 2009 |
| College Spgs 2 | 2 | 2008 | 2008 |
| Mt Hamill | 1 | 2012 | 1981 |
| Exline | 1 | 2008 | 2000 |
| Melrose | 1 | 2007 | 1984 |
| Gaza | 1 | 2009 | 2009 |
| Bryant | 1 | 2024 | 2022 |
| Brooklyn | 1 | 2022 | 2003 |
| Wales | 1 | 2018 | 2018 |
| Maquoketa | 1 | 2024 | 2017 |
| Hudson | 1 | 1978 | 1978 |
| Zearing | 1 | 1974 | 1974 |
| Festina | 1 | 2023 | 2023 |
| Davis Corner | 1 | 1977 | 1977 |
Henslow's Sparrow Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.