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

Bobolink Population Trend in Massachusetts

All statesGrassland birds

Bobolink in Massachusetts has declined: down 44% on the route-weighted index since 1968.

-44%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 →
26Routes 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 Bobolink 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 →

No notable trend signals for Bobolink in Massachusetts. See the full index history below.

Bobolink Population Forecast in Massachusetts

If the recent trend holds, Bobolink in Massachusetts is projected to rise about 22% by 2029 — from 2.8 in 2024 to a central estimate of 3.4 (95% range 1.1–5.7). A 5-year backtest shows a typical error of ±118.5%, with 60% of held-out values landing inside the 95% band.

+22%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 →
3.4Projected 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 →
1.1–5.795% 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 →
±118.5%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, Bobolink in Massachusetts is projected to rise about 22% by 2029 — from 2.8 in 2024 to a central estimate of 3.4 (95% range 1.1–5.7). A 5-year backtest shows a typical error of ±118.5%, with 60% 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 →
20253.51.25.8
20263.51.25.7
20273.41.25.7
20283.41.25.7
20293.41.15.7

Bobolink Survey Routes in Massachusetts

Routes recording Bobolink 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 →
Chesterfield2320241967
Princeton1019761969
Cheshire1019941969
Warren820091968
Pittsfield820161967
Monterey820242019
Cummington620141968
Belchertown420241967
Cummington 2420242015
Hancock320151997
Marion220191966
Littleton220151967
Mansfield219901973
E Pepperell219921966
Warren 2220192010
Ware River120221993
Prattville119981975
Brockton119711969
Newburyport120221967
Maynard120211968
N Oxford120071969
S Barre120241968
N Orange120241969
Sheffield120221969
Holden120241977

Bobolink Population Trend in Other States

californiacoloradoconnecticutidahoillinoisindianaiowakansaskentuckymainemarylandmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-dakotautahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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