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Species · Massachusetts · BBS 2025 Release · 1966–2024

Northern House Wren Population Trend in Massachusetts

All statesForest birds

Northern House Wren in Massachusetts has risen sharply: up 66% on the route-weighted index since 1968.

+66%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 Northern House Wren 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 House Wren has risen sharply in Massachusetts: up 66% on the route-weighted index since 1968.

Northern House Wren Population Forecast in Massachusetts

If the recent trend holds, Northern House Wren in Massachusetts is projected to fall about 15% by 2029 — from 11 in 2024 to a central estimate of 9.1 (95% range 4.8–13). A 5-year backtest shows a typical error of ±40.4%, with 20% of held-out values landing inside the 95% band.

-15%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 →
9.1Projected 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 →
4.8–1395% 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 →
±40.4%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, Northern House Wren in Massachusetts is projected to fall about 15% by 2029 — from 11 in 2024 to a central estimate of 9.1 (95% range 4.8–13). A 5-year backtest shows a typical error of ±40.4%, 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 →
20259.04.713
20269.04.813
20279.04.813
20289.14.813
20299.14.813

Northern House Wren Survey Routes in Massachusetts

Routes recording Northern House Wren 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 →
Brockton3820191967
Belchertown3320241967
Maynard2320221967
Prattville2220191966
S Barre1920241968
Warren 21720242010
Marion1620241966
Princeton1619761969
Holden1620241977
Sheffield1420221969
N Orange1220241968
Pittsfield1120161967
Newburyport1020221967
Mansfield1020241968
E Pepperell1019941966
Warren1020091968
N. Andover820241997
E Dennis620211967
N Oxford620241968
Chesterfield620241967
Monterey620242019
Cummington 2420242015
Littleton320241967
Cummington320141968
Hancock320151997

Northern House Wren Population Trend in Other States

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

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