BirdAnalyst
Species · BCR 19 · BBS 2026 Release · 1966–2025

Tree Swallow In Central Mixed Grass Prairie

All regionsCentral Mixed Grass PrairieAerial insectivores

Tree Swallow in Central Mixed Grass Prairie has surged: up 21× on the route-weighted index since 1977.

21×Since 1977TrendPercent 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 →
50Routes 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 →
40YearsYears 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 →

No notable trend signals for Tree Swallow in Central Mixed Grass Prairie. See the full index history below.

Tree Swallow In Central Mixed Grass Prairie Population Forecast

If the recent trend holds, Tree Swallow in Central Mixed Grass Prairie is projected to fall about 14% by 2030 — from 0.78 in 2025 to a central estimate of 0.67 (95% range 0.36–0.98). A 5-year backtest shows a typical error of ±21.9%, with 80% of held-out values landing inside the 95% band.

-14%Change by 2030TrendPercent 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 →
0.67Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.36–0.9895% 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 →
±21.9%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, Tree Swallow in Central Mixed Grass Prairie is projected to fall about 14% by 2030 — from 0.78 in 2025 to a central estimate of 0.67 (95% range 0.36–0.98). A 5-year backtest shows a typical error of ±21.9%, with 80% of held-out values landing inside the 95% band.19722030
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 →
20260.620.310.93
20270.630.320.94
20280.640.330.96
20290.660.350.97
20300.670.360.98

Routes In Central Mixed Grass Prairie

Routes recording Tree Swallow in Central Mixed Grass 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 →
Piester LakeNEBRASKA142025
KennedyNEBRASKA112025
BartleyNEBRASKA102025
ChambersNEBRASKA72025
Berwyn 2NEBRASKA62025
HendleyNEBRASKA52024
St JohnKANSAS42016
HolbrookNEBRASKA42021
Jewell 2KANSAS32010
SurpriseNEBRASKA32012
Liberty 2NEBRASKA32007
ReedOKLAHOMA32016
CovertKANSAS22013
LibertyNEBRASKA21992
BelvidereNEBRASKA22019
KearneyNEBRASKA22024
SumnerNEBRASKA22025
Swan LakeNEBRASKA22025
JohnstownNEBRASKA22024
GordonNEBRASKA22024
RinggoldNEBRASKA22015
MullenNEBRASKA22023
Wheeler CoNEBRASKA22025
BassettNEBRASKA22024
HollisOKLAHOMA22000

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.