BirdAnalyst
Species · Utah · BBS 2026 Release · 1966–2025

Cliff Swallow Population Trend in Utah

All statesAerial insectivores

Cliff Swallow in Utah has surged: up 91% on the route-weighted index since 1970.

+91%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 →
88Routes 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 →
56YearsYears 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 UtahNotable 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 →

Cliff Swallow has surged in Utah: up 91% on the route-weighted index since 1970.

Cliff Swallow Population Forecast in Utah

If the recent trend holds, Cliff Swallow in Utah is projected to stay roughly flat through 2030, near 24 (95% range 7.8–40). A 5-year backtest shows a typical error of ±65%, with 100% of held-out values landing inside the 95% band.

-0%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 →
24Projected 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 →
7.8–4095% 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 →
±65%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 Utah is projected to stay roughly flat through 2030, near 24 (95% range 7.8–40). A 5-year backtest shows a typical error of ±65%, 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 →
2026237.040
2027237.240
2028247.440
2029247.640
2030247.840

Cliff Swallow Survey Routes in Utah

Routes recording Cliff Swallow in Utah.
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 →
Bear River66820251992
Promontory37220251969
Altonah15920251975
Wellington14320022002
Leamington13020171992
Lynn11620251982
Hardware Ranch9220181994
Boulder6720251968
Beck6019871968
Hill Creek5319951993
Oak City5120231972
Lost Cr. Res5020151997
Saleratus Cr4720181995
Hyrum4519791975
Ant Flat-Ogden Can4020251994
Crawford Mts4020152002
Fayette3920251994
Kamas3520251997
Beryl3020172017
Neponset Res3020181995
Goshen2620251976
Wellington 32420252012
Randolph2120251992
Logan Canyon2020191997
Hanna1820241997

Cliff Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasvermontvirginiawashingtonwest-virginiawisconsinwyoming

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