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

Tree Swallow Population Trend in Colorado

All statesAerial insectivores

Tree Swallow in Colorado has increased: up 40% on the route-weighted index since 1970.

+40%Since 1970
106Routes In State
56Years

Notable Tree Swallow Trends in Colorado

No notable trend signals for Tree Swallow in Colorado. See the full index history below.

Tree Swallow Population Forecast in Colorado

If the recent trend holds, Tree Swallow in Colorado is projected to rise about 108% by 2029 — from 2.0 in 2024 to a central estimate of 4.1 (95% range 0.93–7.3). A 5-year backtest shows a typical error of ±85.9%, with 100% of held-out values landing inside the 95% band.

+108%Change by 2029
4.1Projected 2029 index
0.93–7.395% range
±85.9%Backtest error
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 index95% low95% high
20254.00.867.2
20264.10.887.2
20274.10.897.3
20284.10.917.3
20294.10.937.3

Tree Swallow Survey Routes in Colorado

Routes recording Tree Swallow in Colorado.
Yampa2320231969
Lake City 22220242016
Weston Pass2120001995
Elbert1920221998
Castleton1820241988
Pagosa Spgs1619781968
Rio Grnds Rs1620241993
Lost Lake1520241990
Cheesman Lk1420191977
Trail Ridge Road1420142003
Fox Creek1320241993
Moon Pass1320242014
Heeney1220192017
Lake City1120001988
Tincup1120241994
Gold Hill1120121998
Cortez1020081988
Gribbles Prk1020241995
Rosevale920242009
Mcphee Res.920181997
Tarryall820231988
Stillwater Pass820071999
Kiowa720181993
Kiowa 2720242019
Yellowjacket Pass720241998

Tree Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniaconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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