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

Northern Parula Population Trend in Virginia

All statesForest birds

Northern Parula in Virginia has surged: up 173% on the route-weighted index since 1968.

+173%Since 1968TrendPercent 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 →
79Routes 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 Northern Parula Trends in VirginiaNotable 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 →

Northern Parula has surged in Virginia: up 173% on the route-weighted index since 1968.

Northern Parula Population Forecast in Virginia

If the recent trend holds, Northern Parula in Virginia is projected to fall about 40% by 2029 — from 3.8 in 2024 to a central estimate of 2.3 (95% range 1.5–3.2). A 5-year backtest shows a typical error of ±30.8%, with 40% of held-out values landing inside the 95% band.

-40%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 →
2.3Projected 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 →
1.5–3.295% 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 →
±30.8%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, Northern Parula in Virginia is projected to fall about 40% by 2029 — from 3.8 in 2024 to a central estimate of 2.3 (95% range 1.5–3.2). A 5-year backtest shows a typical error of ±30.8%, with 40% of held-out values landing inside the 95% band.19662029
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 →
20252.21.43.1
20262.31.43.1
20272.31.43.1
20282.31.43.2
20292.31.53.2

Northern Parula Survey Routes in Virginia

Routes recording Northern Parula in Virginia.
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 →
Isom2120241969
Truhart2120241996
Pine Mtn.2020241996
Brandon1620241992
Newsoms1220241968
Nat Tunnel1220241981
Rural Retrt920241982
Gloucester920241992
Surry820241977
Port Royal720191977
Mannboro720241968
Glenwood720231992
Walkers720231992
Church Road620241966
White Stone620241966
Newville620241991
W Augusta520241967
Irisburg520241988
Pw Forest Pk520091992
Appomattox420241996
Tryme320241996
Partlow320151979
David320111969
Amherst320241976
Big Island320241971

Northern Parula Population Trend in Other States

alabamaarkansascaliforniaconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontwest-virginiawisconsin

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