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

Northern House Wren Population Trend in Delaware

All statesForest birds

Northern House Wren in Delaware has edged up: up 11% on the route-weighted index since 1968.

+11%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 →
17Routes 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 DelawareNotable 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 Northern House Wren in Delaware. See the full index history below.

Northern House Wren Population Forecast in Delaware

If the recent trend holds, Northern House Wren in Delaware is projected to rise about 162% by 2029 — from 1.2 in 2024 to a central estimate of 3.1 (95% range 1.7–4.6). A 5-year backtest shows a typical error of ±40.6%, with 80% of held-out values landing inside the 95% band.

+162%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 →
3.1Projected 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 →
1.7–4.695% 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 →
±40.6%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 Delaware is projected to rise about 162% by 2029 — from 1.2 in 2024 to a central estimate of 3.1 (95% range 1.7–4.6). A 5-year backtest shows a typical error of ±40.6%, with 80% 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 →
20253.01.64.4
20263.11.64.5
20273.11.74.5
20283.11.74.5
20293.11.74.6

Northern House Wren Survey Routes in Delaware

Routes recording Northern House Wren in Delaware.
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 →
Bethany Bch719901966
Mt Pleasant420191966
Frederica420141966
Holleyville420041966
Milton 2420172017
Harrington320241966
Milton320161966
Pepperbox320161999
Wilmington220141966
Frankford220121966
Lowes Xrds219781966
Georgetown220221994
Pepperbox 2220242017
Dover119861966
Blackbird120241994
Millsboro120232023
Holleyville 2120192016

Northern House Wren Population Trend in Other States

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

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