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Species · Alaska · BBS 2025 Release · 1966–2024

Cliff Swallow Population Trend in Alaska

All statesAerial insectivores

Cliff Swallow in Alaska has collapsed: down 84% on the route-weighted index since 1978.

-84%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 →
58Routes 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 →
44YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Cliff 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 declinecomputed 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 →

Cliff Swallow has collapsed in Alaska: down 84% on the route-weighted index since 1978.

Cliff Swallow Population Forecast in Alaska

If the recent trend holds, Cliff Swallow in Alaska is projected to fall about 100% by 2029 — from 0.69 in 2024 to a central estimate of 0.00 (95% range 0.00–7.1). A 5-year backtest shows a typical error of ±122%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–7.195% 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 →
±122%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, Cliff Swallow in Alaska is projected to fall about 100% by 2029 — from 0.69 in 2024 to a central estimate of 0.00 (95% range 0.00–7.1). A 5-year backtest shows a typical error of ±122%, with 100% of held-out values landing inside the 95% band.19752029
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 →
20250.000.007.1
20260.000.007.1
20270.000.007.1
20280.000.007.1
20290.000.007.1

Cliff Swallow Survey Routes in Alaska

Routes recording Cliff 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 →
Mcgrath18120221997
Tangle Lakes8519871987
Paxson Lake5519971991
Wasilla5019831983
Sheep Mtn2020041983
Lake Louise1820111995
Birch Lake1520242001
Goose Bay1519821975
Sourdough1320141983
Hather Creek1220032003
Circle1020191987
Cantwell1020152012
Chena Hot Spring 21020042002
Galena (Short)1020231987
Maclaren920241982
Mt. Fairplay920241994
Salmon Lake820042004
Petersville820041986
Hatcher Pass819931986
Seward719921983
Kalifonsky719821982
Teller720241994
Northway620231989
Chena River619881988
Anvik River620052001

Cliff Swallow Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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