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

American Avocet Population Trend in Montana

All statesShorebirds

American Avocet in Montana has surged: up 217% on the route-weighted index since 1971.

+217%Since 1971TrendPercent 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 →
38Routes 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 →
51YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable American Avocet 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 →

American Avocet has surged in Montana: up 217% on the route-weighted index since 1971.

American Avocet Population Forecast in Montana

If the recent trend holds, American Avocet in Montana is projected to fall about 16% by 2029 — from 0.62 in 2024 to a central estimate of 0.52 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±87.8%, with 100% of held-out values landing inside the 95% band.

-16%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 →
0.52Projected 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 →
0.00–1.195% 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 →
±87.8%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, American Avocet in Montana is projected to fall about 16% by 2029 — from 0.62 in 2024 to a central estimate of 0.52 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±87.8%, with 100% 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 →
20250.500.001.1
20260.510.001.1
20270.510.001.1
20280.520.001.1
20290.520.001.1

American Avocet Survey Routes in Montana

Routes recording American Avocet 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 →
Beaverhead4220121981
Glen3220141993
Shawmut3220241982
Glasgow819821982
Highwood820241977
Wise River820122012
Polson719971997
Flatwillow720032003
Dinosaurs H.M.620242022
Painted Rock620021997
Sunburst420051968
Gildford420232018
Whitlash420182013
Flatwillow 2320182018
Hay Lake320191989
Jordan320102010
Forsyth320051992
Shelby320242015
Chinook320172015
Virgelle220231979
Great Falls220241978
Roy220231994
Saco220232023
Sun River220192015
Pablo Res.220012001

American Avocet Population Trend in Other States

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