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

Northern Parula Population Trend in Massachusetts

All statesForest birds

Northern Parula in Massachusetts has surged: up 444% on the route-weighted index since 1970.

+444%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 →
12Routes 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 →
39YearsYears 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 MassachusettsNotable 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 Massachusetts: up 444% on the route-weighted index since 1970.

Northern Parula Population Forecast in Massachusetts

If the recent trend holds, Northern Parula in Massachusetts is projected to fall about 35% by 2029 — from 0.33 in 2024 to a central estimate of 0.22 (95% range 0.06–0.38). A 5-year backtest shows a typical error of ±42.8%, with 60% of held-out values landing inside the 95% band.

-35%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 →
0.22Projected 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 →
0.06–0.3895% 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 →
±42.8%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 Massachusetts is projected to fall about 35% by 2029 — from 0.33 in 2024 to a central estimate of 0.22 (95% range 0.06–0.38). A 5-year backtest shows a typical error of ±42.8%, with 60% 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 →
20250.210.050.37
20260.210.050.37
20270.210.050.37
20280.220.060.38
20290.220.060.38

Northern Parula Survey Routes in Massachusetts

Routes recording Northern Parula in Massachusetts.
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 →
Gay Head420241996
Mansfield319781970
Pittsfield319851969
Chilmark219751975
E Dennis120001992
Marion120221979
Prattville119741968
Cape Cod Ns119931993
Wellfleet 2120242024
Belchertown120032003
Holden119801980
Chesterfield120191979

Northern Parula Population Trend in Other States

alabamaarkansascaliforniaconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsin

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