BirdAnalyst
Species · BCR 19 · BBS 2025 Release · 1966–2024

Tree Swallow In Central Mixed Grass Prairie

All regionsCentral Mixed Grass PrairieAerial insectivores

Tree Swallow in Central Mixed Grass Prairie has surged: up 19× on the route-weighted index since 1977.

19×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 →
47Routes 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 →
39YearsYears 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 →

Tree Swallow has surged in Central Mixed Grass Prairie: up 19× on the route-weighted index since 1977.

Tree Swallow In Central Mixed Grass Prairie Population Forecast

If the recent trend holds, Tree Swallow in Central Mixed Grass Prairie is projected to stay roughly flat through 2029, near 0.64 (95% range 0.33–0.95). A 5-year backtest shows a typical error of ±52.8%, with 60% of held-out values landing inside the 95% band.

-3%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 →
0.64Projected 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 →
0.33–0.9595% 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 →
±52.8%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, Tree Swallow in Central Mixed Grass Prairie is projected to stay roughly flat through 2029, near 0.64 (95% range 0.33–0.95). A 5-year backtest shows a typical error of ±52.8%, with 60% of held-out values landing inside the 95% band.19722029
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 →
20250.590.280.90
20260.600.290.91
20270.610.300.92
20280.630.320.94
20290.640.330.95

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 →
KennedyNEBRASKA112024
BartleyNEBRASKA72024
HendleyNEBRASKA52024
St JohnKANSAS42016
HolbrookNEBRASKA42021
Piester LakeNEBRASKA42024
NenzelNEBRASKA42024
Jewell 2KANSAS32010
SurpriseNEBRASKA32012
Liberty 2NEBRASKA32007
Wheeler CoNEBRASKA32024
ReedOKLAHOMA32016
CovertKANSAS22013
LibertyNEBRASKA21992
BelvidereNEBRASKA22019
KearneyNEBRASKA22024
JohnstownNEBRASKA22024
GordonNEBRASKA22024
RinggoldNEBRASKA22015
BrownleeNEBRASKA22023
MullenNEBRASKA22023
BassettNEBRASKA22024
HollisOKLAHOMA22000
WellingtonKANSAS12006
AlbertKANSAS11982

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