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

Bobolink Population Trend in Maine

All statesGrassland birds

Bobolink in Maine has collapsed: down 84% on the route-weighted index since 1968.

-84%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 →
60Routes 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 MaineNotable 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 declinecomputed 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 →

Bobolink has collapsed in Maine: down 84% on the route-weighted index since 1968.

Bobolink Population Forecast in Maine

If the recent trend holds, Bobolink in Maine is projected to fall about 92% by 2029 — from 2.2 in 2024 to a central estimate of 0.17 (95% range 0.00–8.2). A 5-year backtest shows a typical error of ±19.4%, with 100% of held-out values landing inside the 95% band.

-92%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 →
0.17Projected 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 →
0.00–8.295% 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 →
±19.4%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 Maine is projected to fall about 92% by 2029 — from 2.2 in 2024 to a central estimate of 0.17 (95% range 0.00–8.2). A 5-year backtest shows a typical error of ±19.4%, 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 →
20251.20.009.3
20260.950.009.0
20270.690.008.8
20280.430.008.5
20290.170.008.2

Bobolink Survey Routes in Maine

Routes recording Bobolink in Maine.
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 →
Bowdoin Ctr3520131971
Benton3319801971
Manchester1719951971
Otisfield Gr1420151966
Boundary1220161993
Hermon1120191966
Ludlow1119981968
Washburn1120051979
Cornville1120242012
Harmony920241967
Benedicta920221976
Ft Fairfield920051993
St David920051982
Cape Neddick820221972
Warren819901973
Northfield819811976
Wytopitlock819901976
Ashland820081980
East Troy620191972
Searsport620242002
Hartford520241975
Moose River520061983
Kittery Pt320081967
Newcastle320241971
Freedom320221973

Bobolink Population Trend in Other States

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

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