BirdAnalyst
Species · BCR 17 · BBS 2025 Release · 1966–2024

Tree Swallow In Badlands and Prairies

All regionsBadlands and PrairiesAerial insectivores

Tree Swallow in Badlands and Prairies has surged: up 875% on the route-weighted index since 1971.

+875%Since 1971TrendPercent 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 →
101Routes 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 →
55YearsYears 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 Badlands and Prairies: up 875% on the route-weighted index since 1971.

Tree Swallow In Badlands and Prairies Population Forecast

If the recent trend holds, Tree Swallow in Badlands and Prairies is projected to rise about 109% by 2029 — from 1.1 in 2024 to a central estimate of 2.4 (95% range 0.50–4.3). A 5-year backtest shows a typical error of ±49.1%, with 100% of held-out values landing inside the 95% band.

+109%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 →
2.4Projected 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 →
0.50–4.395% 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 →
±49.1%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, Tree Swallow in Badlands and Prairies is projected to rise about 109% by 2029 — from 1.1 in 2024 to a central estimate of 2.4 (95% range 0.50–4.3). A 5-year backtest shows a typical error of ±49.1%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20252.20.344.1
20262.30.384.2
20272.30.424.2
20282.30.464.2
20292.40.504.3

Routes In Badlands and Prairies

Routes recording Tree Swallow in Badlands and Prairies.
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 →
IsabelSOUTH-DAKOTA882015
St XavierMONTANA452010
PromiseSOUTH-DAKOTA452015
ArvadaWYOMING222022
Two DotMONTANA212024
RochfordSOUTH-DAKOTA152018
RosebudSOUTH-DAKOTA132011
BadlandsSOUTH-DAKOTA132012
Black FoxSOUTH-DAKOTA112017
GorhamNORTH-DAKOTA102018
Reed PointMONTANA92024
BentleyNORTH-DAKOTA82018
DaytonWYOMING82024
St Xavier 2MONTANA72023
Ft ThompsonSOUTH-DAKOTA72007
Maynard CouleeMONTANA62024
CircleMONTANA52023
BrandenbergMONTANA52019
VolunteerSOUTH-DAKOTA52017
Cedar PassSOUTH-DAKOTA52016
LacreekSOUTH-DAKOTA52023
FlatwillowMONTANA41992
WebsterMONTANA42023
Chuffey SpringMONTANA42023
TobaccoNORTH-DAKOTA42019

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