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

Tree Swallow Population Trend in Wyoming

All statesAerial insectivores

Tree Swallow in Wyoming has surged: up 96% on the route-weighted index since 1970.

+96%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 →
93Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Tree 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 →

Tree Swallow has surged in Wyoming: up 96% on the route-weighted index since 1970.

Tree Swallow Population Forecast in Wyoming

If the recent trend holds, Tree Swallow in Wyoming is projected to fall about 14% by 2030 — from 3.6 in 2025 to a central estimate of 3.0 (95% range 0.14–6.0). A 5-year backtest shows a typical error of ±16.1%, with 100% of held-out values landing inside the 95% band.

-14%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 →
0.14–6.095% 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 →
±16.1%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, Tree Swallow in Wyoming is projected to fall about 14% by 2030 — from 3.6 in 2025 to a central estimate of 3.0 (95% range 0.14–6.0). A 5-year backtest shows a typical error of ±16.1%, 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 →
20263.00.125.9
20273.00.135.9
20283.00.135.9
20293.00.146.0
20303.00.146.0

Tree Swallow Survey Routes in Wyoming

Routes recording Tree 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 →
Green River6719841977
Yellowstone5020251987
Boulder3220251999
Ne Entrance2520251982
Seedskadee1920231986
Seedskadee 21820242024
Harmony1720251982
Dayton1620251983
Hayden Val1619861985
Dubois1420251968
Savery1419951989
Wilson1420251979
Soda Lake1320251980
Crazy Woman1220241979
Fox Park1220251993
Alpine1120251979
Buckskin Mtn920251982
Otto820151970
Mammoth820251982
Arvada820251987
Sussex820252005
Riverside720251971
Soda Well720251983
Big Sandy720251983
Walcott720251985

Tree Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsin

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