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Species · Wyoming · BBS 2026 Release · 1966–2025

Violet-green Swallow Population Trend in Wyoming

All statesAerial insectivores

Violet-green Swallow in Wyoming has surged: up 255% on the route-weighted index since 1973.

+255%Since 1973TrendPercent 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 →
98Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
54YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Violet-green Swallow Trends in WyomingNotable 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 surged in Wyoming: up 255% on the route-weighted index since 1973.

Violet-green Swallow Population Forecast in Wyoming

If the recent trend holds, Violet-green Swallow in Wyoming is projected to stay roughly flat through 2030, near 3.0 (95% range 0.94–5.1). A 5-year backtest shows a typical error of ±41.5%, with 100% of held-out values landing inside the 95% band.

+9%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 →
3.0Projected 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 →
0.94–5.195% 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 →
±41.5%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 Wyoming is projected to stay roughly flat through 2030, near 3.0 (95% range 0.94–5.1). A 5-year backtest shows a typical error of ±41.5%, with 100% of held-out values landing inside the 95% band.19712030
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 →
20262.90.895.0
20273.00.905.0
20283.00.915.0
20293.00.935.0
20303.00.945.1

Violet-green Swallow Survey Routes in Wyoming

Routes recording Violet-green Swallow in Wyoming.
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 →
Dubois5120251972
Moskee5120011980
Hunter Peak3220251982
Kaycee2820252025
Crowheart2220161987
Moskee 22220212002
Basin2020251983
Wilson1520251982
Mammoth1420251982
Brookhurst1320112000
Green River1219841977
Hayden Val1219861985
Moskee 31120242022
Yellowstone1020251987
Cody820251988
Soda Lake819931981
Rawlins819991997
Fontenelle720251982
Meeteetse720251991
Meadowdale720251990
Seedskadee 2720242024
Savery619891989
Moose620251976
Rock Springs620221977
Fox Park620251992

Violet-green Swallow Population Trend in Other States

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