BirdAnalyst
Species · BCR 22 · BBS 2025 Release · 1966–2024

Eurasian Tree Sparrow In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieGeneralists

Eurasian Tree Sparrow in Eastern Tallgrass Prairie has surged: up 707% on the route-weighted index since 1969.

+707%Since 1969TrendPercent 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 →
59Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 →

Eurasian Tree Sparrow has surged in Eastern Tallgrass Prairie: up 706% on the route-weighted index since 1969.

Eurasian Tree Sparrow In Eastern Tallgrass Prairie Population Forecast

If the recent trend holds, Eurasian Tree Sparrow in Eastern Tallgrass Prairie is projected to fall about 23% by 2029 — from 0.94 in 2024 to a central estimate of 0.73 (95% range 0.34–1.1). A 5-year backtest shows a typical error of ±33.1%, with 60% of held-out values landing inside the 95% band.

-23%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 →
0.34–1.195% 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 →
±33.1%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, Eurasian Tree Sparrow in Eastern Tallgrass Prairie is projected to fall about 23% by 2029 — from 0.94 in 2024 to a central estimate of 0.73 (95% range 0.34–1.1). A 5-year backtest shows a typical error of ±33.1%, with 60% of held-out values landing inside the 95% band.19672029
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 →
20250.680.301.1
20260.690.311.1
20270.700.321.1
20280.710.331.1
20290.730.341.1

Routes In Eastern Tallgrass Prairie

Routes recording Eurasian Tree Sparrow in Eastern Tallgrass Prairie.
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 →
CameronILLINOIS192024
West LibertyIOWA182024
Terre HauteILLINOIS142024
ConcordILLINOIS142023
GreenviewILLINOIS142024
WilliamsfldILLINOIS122024
BudaILLINOIS102023
BelleviewILLINOIS92024
SherrardILLINOIS92024
KeithsburgILLINOIS92022
RensselaerMISSOURI82019
Duncan MillsILLINOIS72024
Kahoka2MISSOURI72024
ChandlervillILLINOIS62024
AthensILLINOIS62016
MillwoodMISSOURI62024
Mill CreekILLINOIS52023
PutnamILLINOIS52024
ClaytonILLINOIS52024
EubanksILLINOIS52024
AtkinsonILLINOIS42024
Camp PointILLINOIS42024
WilliamsburgIOWA42023
Deer CreekILLINOIS32024
St MorganILLINOIS32009

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