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Species · Alaska · BBS 2026 Release · 1966–2025

Violet-green Swallow Population Trend in Alaska

All statesAerial insectivores

Violet-green Swallow in Alaska has risen sharply: up 54% on the route-weighted index since 1978.

+54%Since 1978TrendPercent 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 →
80Routes 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 →
46YearsYears 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 AlaskaNotable 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 Alaska: up 54% on the route-weighted index since 1978.

Violet-green Swallow Population Forecast in Alaska

If the recent trend holds, Violet-green Swallow in Alaska is projected to fall about 53% by 2030 — from 1.7 in 2025 to a central estimate of 0.81 (95% range 0.00–2.5). A 5-year backtest shows a typical error of ±37.6%, with 100% of held-out values landing inside the 95% band.

-53%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 →
0.81Projected 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 →
0.00–2.595% 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 →
±37.6%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 Alaska is projected to fall about 53% by 2030 — from 1.7 in 2025 to a central estimate of 0.81 (95% range 0.00–2.5). A 5-year backtest shows a typical error of ±37.6%, 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 →
20260.920.002.6
20270.900.002.6
20280.870.002.6
20290.840.002.6
20300.810.002.5

Violet-green Swallow Survey Routes in Alaska

Routes recording Violet-green Swallow in Alaska.
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 →
Thompson Pas4220251983
Seward2819921982
Matanuska1419831983
Hope1120251993
Haines1020251993
Circle820111987
Harlequin L.820052005
Kanuti Canyn820241993
Kachemak720251986
Kenny Lake620251983
Anchor River620251984
Eagle520251982
Homer519821978
Juneau520231985
Mcgrath520221997
Hyder520091994
Tatalina520191995
Chicken420241992
Paxson Lake419951995
Delta420072007
Chistochina320251994
Goose Bay319821982
Willow320251994
Sheep Mtn320251983
Katmai N.P.320052005

Violet-green Swallow Population Trend in Other States

arizonacaliforniacoloradoidahomontananebraskanevadanew-mexiconorth-dakotaoregonsouth-dakotatexasutahwashingtonwyoming

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