BirdAnalyst
Species · Alaska · BBS 2025 Release · 1966–2024

Violet-green Swallow Population Trend in Alaska

All statesAerial insectivores

Violet-green Swallow in Alaska has risen sharply: up 51% on the route-weighted index since 1978.

+51%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 →
45YearsYears 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 51% 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 50% by 2029 — from 1.5 in 2024 to a central estimate of 0.77 (95% range 0.00–2.5). A 5-year backtest shows a typical error of ±38.7%, with 100% of held-out values landing inside the 95% band.

-50%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 →
0.77Projected 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 →
0.00–2.595% 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 →
±38.7%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 50% by 2029 — from 1.5 in 2024 to a central estimate of 0.77 (95% range 0.00–2.5). A 5-year backtest shows a typical error of ±38.7%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.890.002.6
20260.860.002.6
20270.830.002.5
20280.800.002.5
20290.770.002.5

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 →
Seward2819921982
Matanuska1419831983
Hope1420241993
Eagle1320241982
Willow1120241994
Kenny Lake1120241983
Chistochina1020221994
Haines1020241993
Kachemak1020241986
Thompson Pas920241983
Circle820111987
Anchor River820241984
Harlequin L.820052005
Kanuti Canyn820241993
Homer519821978
Juneau520231985
Sheep Mtn520141983
Mcgrath520221997
Skagway520241994
Hyder520091994
Tatalina520191995
Chicken420241992
Paxson Lake419951995
Delta420072007
Goose Bay319821982

Violet-green Swallow Population Trend in Other States

arizonacaliforniacoloradoidahomontananebraskanevadanew-mexiconorth-dakotaoregonsouth-dakotatexasutahwashingtonwyoming

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