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

Gray Partridge Population Trend in Montana

All statesGeneralists

Gray Partridge in Montana has risen sharply: up 70% on the route-weighted index since 1970.

+70%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 →
55Routes 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 Gray Partridge 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 →

Gray Partridge has risen sharply in Montana: up 70% on the route-weighted index since 1970.

Gray Partridge Population Forecast in Montana

If the recent trend holds, Gray Partridge in Montana is projected to fall about 61% by 2029 — from 0.83 in 2024 to a central estimate of 0.32 (95% range 0.00–0.84). A 5-year backtest shows a typical error of ±82.4%, with 80% of held-out values landing inside the 95% band.

-61%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 →
0.32Projected 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 →
0.00–0.8495% 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 →
±82.4%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, Gray Partridge in Montana is projected to fall about 61% by 2029 — from 0.83 in 2024 to a central estimate of 0.32 (95% range 0.00–0.84). A 5-year backtest shows a typical error of ±82.4%, 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 →
20250.330.000.84
20260.330.000.84
20270.330.000.84
20280.330.000.84
20290.320.000.84

Gray Partridge Survey Routes in Montana

Routes recording Gray Partridge 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 →
Clyde Park1220242021
Circle820131973
Glentana720242015
Redstone620241970
Polson620241977
Glasgow520241968
Wolf Point520242015
Pablo Res.520051997
Virgelle420241979
Lambert420242021
Whitlash420222009
Oswego320231978
Highwood320231970
Flatwillow320071978
Reed Point320122008
Laurel320191973
Lindsay320242016
Hay Lake220221989
Harlem220171988
Glen220211979
Willow Creek 2220241984
Augusta219891984
Roy220241988
Brusett219941983
Savage219931979

Gray Partridge Population Trend in Other States

idahoillinoisindianaiowaminnesotanebraskanevadanew-yorknorth-dakotaoregonsouth-dakotautahwashingtonwisconsinwyoming

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