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

Tree Swallow Population Trend in Wyoming

All statesAerial insectivores

Tree Swallow in Wyoming has risen sharply: up 71% on the route-weighted index since 1970.

+71%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 →
91Routes 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 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 risen sharply in Wyoming: up 71% 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 rise about 23% by 2029 — from 2.4 in 2024 to a central estimate of 3.0 (95% range 0.04–5.9). A 5-year backtest shows a typical error of ±19.3%, with 100% of held-out values landing inside the 95% band.

+23%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 →
3.0Projected 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 →
0.04–5.995% 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 →
±19.3%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 rise about 23% by 2029 — from 2.4 in 2024 to a central estimate of 3.0 (95% range 0.04–5.9). A 5-year backtest shows a typical error of ±19.3%, 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 →
20253.00.035.9
20263.00.035.9
20273.00.035.9
20283.00.045.9
20293.00.045.9

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
Cody3220241989
Arvada2220221987
Meeteetse2020241991
Seedskadee1920231986
Boulder1820241999
Seedskadee 21820242024
Hayden Val1619861985
Savery1419951989
Mammoth1420241982
Crazy Woman1220241979
Ryan Park1120231993
Harmony1120231982
Walcott1020241985
Alpine920241979
Otto820151970
Dayton820241983
Yellowstone820221987
Dubois620241968
Wilson620241979
Mtn View620241980
Hunter Peak520241982
Horse Creek520241983
Cheyenne520162001
Ne Entrance420211982

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 2026-05-22.