BirdAnalyst
Species · North Dakota · BBS 2026 Release · 1966–2025

Warbling Vireo Population Trend in North Dakota

All statesForest birds

Warbling Vireo in North Dakota has surged: up 259% on the route-weighted index since 1969.

+259%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 →
50Routes 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Warbling Vireo Trends in North DakotaNotable 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 →

Warbling Vireo has surged in North Dakota: up 259% on the route-weighted index since 1969.

Warbling Vireo Population Forecast in North Dakota

If the recent trend holds, Warbling Vireo in North Dakota is projected to rise about 83% by 2030 — from 3.8 in 2025 to a central estimate of 6.9 (95% range 5.2–8.7). A 5-year backtest shows a typical error of ±21.5%, with 80% of held-out values landing inside the 95% band.

+83%Change by 2030TrendPercent 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 →
6.9Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
5.2–8.795% 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 →
±21.5%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, Warbling Vireo in North Dakota is projected to rise about 83% by 2030 — from 3.8 in 2025 to a central estimate of 6.9 (95% range 5.2–8.7). A 5-year backtest shows a typical error of ±21.5%, with 80% of held-out values landing inside the 95% band.19672030
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 →
20266.64.88.3
20276.74.98.4
20286.75.08.5
20296.85.18.6
20306.95.28.7

Warbling Vireo Survey Routes in North Dakota

Routes recording Warbling Vireo in North Dakota.
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 →
Turtle Mtns2720251980
Loraine1520191982
Denbigh1420251968
Kempton1120171967
Lake George1020231968
Cooperstown1020251969
Walcott620231967
Edgeley620251980
Horsehead Lk620251980
Forman520251968
Sydney519831979
Wimbledon520251981
Buchanan520251967
Webster520011989
Emerado420251973
Powers Lake420251982
Solen420252005
Rolla320071969
Carpio320231967
Stanley320251968
Sheyenne Lk320251980
Braddock320231988
Carson320231988
Abercrombie 2320172013
Regan220251974

Warbling Vireo Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.