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

House Sparrow Population Trend in Maine

All statesGeneralists

House Sparrow in Maine has fallen sharply: down 52% on the route-weighted index since 1968.

-52%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 →
55Routes 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 House Sparrow 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 →

House Sparrow has fallen sharply in Maine: down 52% on the route-weighted index since 1968.

House Sparrow Population Forecast in Maine

If the recent trend holds, House Sparrow in Maine is projected to fall about 91% by 2029 — from 8.3 in 2024 to a central estimate of 0.73 (95% range 0.00–7.8). A 5-year backtest shows a typical error of ±106.9%, with 40% of held-out values landing inside the 95% band.

-91%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 →
0.73Projected 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 →
0.00–7.895% 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 →
±106.9%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, House Sparrow in Maine is projected to fall about 91% by 2029 — from 8.3 in 2024 to a central estimate of 0.73 (95% range 0.00–7.8). A 5-year backtest shows a typical error of ±106.9%, with 40% 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 →
20251.20.008.3
20261.10.008.2
20270.990.008.0
20280.860.007.9
20290.730.007.8

House Sparrow Survey Routes in Maine

Routes recording House Sparrow 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 →
Kittery Pt5520241966
Westbrook3920241977
Cornville3220242012
Brooks2420181977
Bowdoin Ctr1820211971
Ludlow1719951968
Manchester1219951973
East Troy1020171972
Brownfield1020092009
Rome1020241996
Biddeford920191975
Cooper819811976
Moose River819861983
Harmony720241967
Benton719801971
Carrabassett719861984
Washburn720051979
Otisfield Gr620151966
Grnd Lk Strm619661966
Bethel520161972
Turner520101972
Hermon520181966
Aurora519831983
Cambridge420131967
Ft Fairfield420051993

House Sparrow Population Trend in Other States

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

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