BirdAnalyst
Species · BCR 18 · BBS 2025 Release · 1966–2024

Tree Swallow In Shortgrass Prairie

All regionsShortgrass PrairieAerial insectivores

Tree Swallow in Shortgrass Prairie has surged: up 855% on the route-weighted index since 1993.

+855%Since 1993TrendPercent 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 →
24Routes 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 →
29YearsYears 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 Shortgrass Prairie: up 855% on the route-weighted index since 1993.

Tree Swallow In Shortgrass Prairie Population Forecast

If the recent trend holds, Tree Swallow in Shortgrass Prairie is projected to rise about 51% by 2029 — from 0.22 in 2024 to a central estimate of 0.33 (95% range 0.07–0.58). A 5-year backtest shows a typical error of ±113.5%, with 80% of held-out values landing inside the 95% band.

+51%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 →
0.33Projected 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 →
0.07–0.5895% 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 →
±113.5%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 Shortgrass Prairie is projected to rise about 51% by 2029 — from 0.22 in 2024 to a central estimate of 0.33 (95% range 0.07–0.58). A 5-year backtest shows a typical error of ±113.5%, with 80% of held-out values landing inside the 95% band.19812029
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 →
20250.310.060.56
20260.320.060.57
20270.320.070.57
20280.320.070.58
20290.330.070.58

Routes In Shortgrass Prairie

Routes recording Tree Swallow in Shortgrass 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 →
ElbertCOLORADO192022
KiowaCOLORADO72018
Kiowa 2COLORADO72024
NeegrandeCOLORADO52019
CheyenneWYOMING52016
Hay SpringsNEBRASKA42024
ArsenalCOLORADO32015
Pine RidgeNEBRASKA32022
VillegreenCOLORADO22004
JulesburgCOLORADO22018
Arsenal 2COLORADO22023
MaxwellNEW-MEXICO22014
FrionaTEXAS22001
YoderWYOMING22024
LingleWYOMING22024
ChugwaterWYOMING22024
HudsonCOLORADO12024
Last Chance 2COLORADO12022
Doyle BridgeCOLORADO11993
EllicottCOLORADO12018
DaltonNEBRASKA12015
Murray LakeNEBRASKA12017
CrawfordNEBRASKA12019
Pine BluffWYOMING11981

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