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

Western Meadowlark Population Trend in Iowa

All statesGrassland birds

Western Meadowlark in Iowa has collapsed: down 95% on the route-weighted index since 1969.

-95%Since 1969TrendPercent 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 →
39Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Western Meadowlark Trends in IowaNotable 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 declinecomputed 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 →

Western Meadowlark has collapsed in Iowa: down 95% on the route-weighted index since 1969.

Western Meadowlark Population Forecast in Iowa

If the recent trend holds, Western Meadowlark in Iowa is projected to fall about 100% by 2029 — from 3.2 in 2024 to a central estimate of 0.00 (95% range 0.00–18). A 5-year backtest shows a typical error of ±189.4%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–1895% 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 →
±189.4%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, Western Meadowlark in Iowa is projected to fall about 100% by 2029 — from 3.2 in 2024 to a central estimate of 0.00 (95% range 0.00–18). A 5-year backtest shows a typical error of ±189.4%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.000.0018
20260.000.0018
20270.000.0018
20280.000.0018
20290.000.0018

Western Meadowlark Survey Routes in Iowa

Routes recording Western Meadowlark in Iowa.
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 →
College Spgs6720041979
Zearing6219951967
Cedar Valley5219971967
College Spgs 22520232005
Scranton2120241967
Bedford1920181979
Wales1620181979
Washta1620141967
Dinsdale1420241968
Kanawha1020241967
Garner919931971
Brooklyn720221967
Panther720241967
Clare720191967
Gaza720231969
Rock Valley720191968
Prairieburg520191967
Tipton520241993
Lafayette420192003
West Liberty320241968
Washington320241967
Titonka320231968
Desmoines219791968
Neola220151968
Pierson220191968

Western Meadowlark Population Trend in Other States

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