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

Northern Mockingbird Population Trend in Massachusetts

All statesGeneralists

Northern Mockingbird in Massachusetts has surged: up 230% on the route-weighted index since 1968.

+230%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 →
30Routes 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 Mockingbird 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 Mockingbird has surged in Massachusetts: up 230% on the route-weighted index since 1968.

Northern Mockingbird Population Forecast in Massachusetts

If the recent trend holds, Northern Mockingbird in Massachusetts is projected to rise about 72% by 2029 — from 1.1 in 2024 to a central estimate of 1.8 (95% range 0.00–7.1). A 5-year backtest shows a typical error of ±140.5%, with 100% of held-out values landing inside the 95% band.

+72%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 →
1.8Projected 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 →
0.00–7.195% 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 →
±140.5%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, Northern Mockingbird in Massachusetts is projected to rise about 72% by 2029 — from 1.1 in 2024 to a central estimate of 1.8 (95% range 0.00–7.1). A 5-year backtest shows a typical error of ±140.5%, 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 →
20252.10.007.4
20262.00.007.3
20272.00.007.3
20281.90.007.2
20291.80.007.1

Northern Mockingbird Survey Routes in Massachusetts

Routes recording Northern Mockingbird 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 →
E Pepperell1519941971
Pittsfield619921979
Newburyport520221970
Cheshire519941971
Mansfield420241972
Warren420091968
Chilmark319831971
N Oxford320241974
Cape Cod Ns319991989
Gay Head320241996
Prattville220191974
Maynard220221971
Littleton220241974
Princeton219751971
Belchertown220241973
Chesterfield220061978
Ware River219931993
N. Andover220191995
E Dennis120191969
Marion120221970
Wellfleet120051966
Brockton120191967
S Barre120211976
N Orange120001986
Cummington119831981

Northern Mockingbird Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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