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

Gray Catbird Population Trend in Massachusetts

All statesGeneralists

Gray Catbird in Massachusetts has risen sharply: up 59% on the route-weighted index since 1968.

+59%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 →
32Routes 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 Gray Catbird 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 →

Gray Catbird has risen sharply in Massachusetts: up 59% on the route-weighted index since 1968.

Gray Catbird Population Forecast in Massachusetts

If the recent trend holds, Gray Catbird in Massachusetts is projected to stay roughly flat through 2029, near 30 (95% range 23–37). A 5-year backtest shows a typical error of ±22%, with 20% of held-out values landing inside the 95% band.

-10%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 →
30Projected 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 →
23–3795% 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 →
±22%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, Gray Catbird in Massachusetts is projected to stay roughly flat through 2029, near 30 (95% range 23–37). A 5-year backtest shows a typical error of ±22%, with 20% 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 →
2025302336
2026302337
2027302337
2028302337
2029302337

Gray Catbird Survey Routes in Massachusetts

Routes recording Gray Catbird 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 →
Brockton7520191967
Wellfleet 26520242016
Marion6220241966
Newburyport5720221967
Gay Head5420241996
S Barre5120241968
Chilmark4619831969
Belchertown4520241967
Holden3520241977
N Oxford3420241968
Pittsfield3420161967
E Dennis3320211967
Warren 23320242010
Prattville3120191966
Mansfield3120241968
Cheshire3019941969
Wellfleet2920071966
Warren2520091968
Monterey2420242019
E Pepperell2219941966
Maynard2120221967
Chesterfield1820241967
Littleton1620241967
N Orange1520241968
Ware River1520221993

Gray Catbird Population Trend in Other States

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

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