BirdAnalyst
Species · BCR 16 · BBS 2026 Release · 1966–2025

Violet-green Swallow In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauAerial insectivores

Violet-green Swallow in Southern Rockies / Colorado Plateau has risen sharply: up 53% on the route-weighted index since 1970.

+53%Since 1970TrendPercent 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 →
230Routes 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 →

Violet-green Swallow has risen sharply in Southern Rockies / Colorado Plateau: up 53% on the route-weighted index since 1970.

Violet-green Swallow In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Violet-green Swallow in Southern Rockies / Colorado Plateau is projected to stay roughly flat through 2030, near 9.7 (95% range 3.9–15). A 5-year backtest shows a typical error of ±23.5%, with 100% of held-out values landing inside the 95% band.

-2%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 →
9.7Projected 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 →
3.9–1595% 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 →
±23.5%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, Violet-green Swallow in Southern Rockies / Colorado Plateau is projected to stay roughly flat through 2030, near 9.7 (95% range 3.9–15). A 5-year backtest shows a typical error of ±23.5%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20269.63.815
20279.63.815
20289.73.915
20299.73.915
20309.73.915

Routes In Southern Rockies / Colorado Plateau

Routes recording Violet-green Swallow in Southern Rockies / Colorado Plateau.
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 →
AspenCOLORADO942025
Dry ParkARIZONA822025
Dolores RivCOLORADO722025
Mesaverde NpCOLORADO682025
TarryallCOLORADO602025
Blackhead PkCOLORADO602025
Rifle FallsCOLORADO552025
Dunckley PasCOLORADO442025
Stillwater PassCOLORADO402009
Fox CreekCOLORADO362025
Pagosa SpgsCOLORADO351982
ColonaCOLORADO332014
MoabUTAH322025
CokedaleCOLORADO312025
GallinasNEW-MEXICO302025
La SalUTAH292000
Gold HillCOLORADO262012
CanyonlandsUTAH262006
BufordCOLORADO252025
Owl Creek PassCOLORADO252025
Angel Fire 2NEW-MEXICO252025
Main CanyonUTAH252025
TsaileARIZONA242023
ParlinCOLORADO242025
Colona 2COLORADO222025

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