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

Yellow-throated Vireo Population Trend in Iowa

All statesForest birds

Yellow-throated Vireo in Iowa has risen sharply: up 69% on the route-weighted index since 1970.

+69%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 →
25Routes 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 →
52YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Yellow-throated Vireo 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 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 →

Yellow-throated Vireo has risen sharply in Iowa: up 69% on the route-weighted index since 1970.

Yellow-throated Vireo Population Forecast in Iowa

If the recent trend holds, Yellow-throated Vireo in Iowa is projected to fall about 21% by 2029 — from 0.36 in 2024 to a central estimate of 0.29 (95% range 0.04–0.53). A 5-year backtest shows a typical error of ±36.3%, 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 →
0.29Projected 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 →
0.04–0.5395% 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 →
±36.3%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, Yellow-throated Vireo in Iowa is projected to fall about 21% by 2029 — from 0.36 in 2024 to a central estimate of 0.29 (95% range 0.04–0.53). A 5-year backtest shows a typical error of ±36.3%, with 80% 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 →
20250.270.030.52
20260.280.030.52
20270.280.030.53
20280.280.040.53
20290.290.040.53

Yellow-throated Vireo Survey Routes in Iowa

Routes recording Yellow-throated Vireo 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 →
Red Rock320241973
Alice319991968
College Spgs 2320212019
Hudson220211990
Washta220142008
Mt Hamill120241967
Exline120241978
Melrose120241998
Bryant120041991
West Liberty120231968
Cedar Valley119971967
Brooklyn120221993
Williamsburg119801980
Panther120222008
Washington120161973
Wales119921992
Maquoketa120241995
Prairieburg120131967
Clare120011984
Festina120241970
Davis Corner120221988
Garner119871987
Rock Valley119861986
Tipton119991993
Lafayette120192003

Yellow-throated Vireo Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsin

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