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

House Sparrow Population Trend in Arizona

All statesGeneralists

House Sparrow in Arizona has fallen sharply: down 64% on the route-weighted index since 1970.

-64%Since 1970TrendPercent 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 →
71Routes 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 →
56YearsYears 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 ArizonaNotable 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 Arizona: down 64% on the route-weighted index since 1970.

House Sparrow Population Forecast in Arizona

If the recent trend holds, House Sparrow in Arizona is projected to fall about 21% by 2029 — from 7.9 in 2024 to a central estimate of 6.2 (95% range 0.00–19). A 5-year backtest shows a typical error of ±16.8%, with 100% of held-out values landing inside the 95% band.

-21%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 →
6.2Projected 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 →
0.00–1995% 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 →
±16.8%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 Arizona is projected to fall about 21% by 2029 — from 7.9 in 2024 to a central estimate of 6.2 (95% range 0.00–19). A 5-year backtest shows a typical error of ±16.8%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20258.00.0021
20267.60.0021
20277.10.0020
20286.70.0020
20296.20.0019

House Sparrow Survey Routes in Arizona

Routes recording House Sparrow in Arizona.
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 →
Coolidge14519851974
New River10720161974
Peach Spring7620241992
Florence6419881968
Cactus Forest5420241991
Vicksburg3019891968
Laguna3020231968
Seligman2820241991
Red Rock 22620242015
Palo Verde2520131992
Page2420191993
Ajo 22120222009
Pomerene2020241970
Mcneal1920241992
Araby1620231992
Prescott1520221974
Palo Verde 21420242014
Red Rock1420141992
Hope 21320192014
Ajo1220081968
Portal1220061982
Amado1220231993
Greasewood1120031993
Castle Butte1020071992
Skull Valley1020241996

House Sparrow Population Trend in Other States

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

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