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

Brown Creeper Population Trend in Massachusetts

All statesForest birds

Brown Creeper in Massachusetts has surged: up 462% on the route-weighted index since 1968.

+462%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 →
31Routes 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 Brown Creeper 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 →

Brown Creeper has surged in Massachusetts: up 462% on the route-weighted index since 1968.

Brown Creeper Population Forecast in Massachusetts

If the recent trend holds, Brown Creeper in Massachusetts is projected to fall about 16% by 2029 — from 1.2 in 2024 to a central estimate of 1.0 (95% range 0.56–1.5). A 5-year backtest shows a typical error of ±21.7%, with 100% of held-out values landing inside the 95% band.

-16%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 →
1.0Projected 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 →
0.56–1.595% 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 →
±21.7%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, Brown Creeper in Massachusetts is projected to fall about 16% by 2029 — from 1.2 in 2024 to a central estimate of 1.0 (95% range 0.56–1.5). A 5-year backtest shows a typical error of ±21.7%, with 100% 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 →
20250.960.511.4
20260.970.521.4
20270.980.531.4
20281.000.551.4
20291.00.561.5

Brown Creeper Survey Routes in Massachusetts

Routes recording Brown Creeper 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 →
N Orange720241971
Belchertown320241968
Maynard220221968
Cummington220141970
Sheffield220131970
Monterey220242019
Cummington 2220242015
Hancock220092001
E Dennis120081978
Chilmark119811981
Marion120221977
Wellfleet119961966
Prattville120181995
Brockton120172017
Newburyport120211967
Littleton120241988
N Oxford119961971
Mansfield120012001
Princeton119751975
E Pepperell119921983
Warren120031974
S Barre120241978
Chesterfield120241968
Pittsfield120161970
Ware River120221993

Brown Creeper Population Trend in Other States

alaskaarizonacaliforniacoloradoconnecticutidahoillinoisindianaiowamainemarylandmichiganminnesotamontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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