BirdAnalyst
Species · Montana · BBS 2025 Release · 1966–2024

Savannah Sparrow Population Trend in Montana

All statesGrassland birds

Savannah Sparrow in Montana has surged: up 313% on the route-weighted index since 1970.

+313%Since 1970TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
98Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Savannah Sparrow Trends in MontanaNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Savannah Sparrow has surged in Montana: up 313% on the route-weighted index since 1970.

Savannah Sparrow Population Forecast in Montana

If the recent trend holds, Savannah Sparrow in Montana is projected to rise about 21% by 2029 — from 13 in 2024 to a central estimate of 16 (95% range 10–22). A 5-year backtest shows a typical error of ±33.3%, with 80% of held-out values landing inside the 95% band.

+21%Change by 2029TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
16Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
10–2295% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±33.3%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Savannah Sparrow in Montana is projected to rise about 21% by 2029 — from 13 in 2024 to a central estimate of 16 (95% range 10–22). A 5-year backtest shows a typical error of ±33.3%, with 80% of held-out values landing inside the 95% band.19682029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
2025169.721
2026169.921
2027161022
2028161022
2029161022

Savannah Sparrow Survey Routes in Montana

Routes recording Savannah Sparrow in Montana.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Beaverhead12520241973
Pablo Res.11320241995
Sunburst7920071971
Two Dot6820241976
Augusta6020241976
Chestnut6020241968
Raynesford5120242016
Red Rock4520241975
Westby4520242015
St Mary4420081968
Church Hill4020242017
Redstone3520241968
Willow Creek 23220241982
Clyde Park3220242018
Hay Lake2920221988
Shelby2920242015
Polson2820241972
St. Mary 22820242009
Twin Bridges2419761968
Whitlash2420242009
Lambert2320242021
Virgelle2220241979
Gildford2220242015
Freeman Creek2120162015
Fort Logan2120242018

Savannah Sparrow Population Trend in Other States

alaskaarizonacaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourinebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.