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

Rock Wren Population Trend in Colorado

All statesForest birds

Rock Wren in Colorado has surged: up 252% on the route-weighted index since 1970.

+252%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 →
116Routes 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 Rock Wren Trends in ColoradoNotable 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 →

Rock Wren has surged in Colorado: up 252% on the route-weighted index since 1970.

Rock Wren Population Forecast in Colorado

If the recent trend holds, Rock Wren in Colorado is projected to stay roughly flat through 2029, near 1.7 (95% range 0.91–2.4). A 5-year backtest shows a typical error of ±18.2%, with 100% of held-out values landing inside the 95% band.

+1%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 →
1.7Projected 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 →
0.91–2.495% 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 →
±18.2%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, Rock Wren in Colorado is projected to stay roughly flat through 2029, near 1.7 (95% range 0.91–2.4). A 5-year backtest shows a typical error of ±18.2%, 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 →
20251.60.872.4
20261.60.882.4
20271.70.892.4
20281.70.902.4
20291.70.912.4

Rock Wren Survey Routes in Colorado

Routes recording Rock Wren in Colorado.
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 →
Baxter Pass2420241995
Cokedale1920241995
Wray Gulch1820231988
Ludlow1620161998
Delta1320211973
Powderhorn1320231998
Angora1120241998
Moon Pass1020242000
Douglas Pass820241982
Black Sulphur Cr820242015
Rosevale720242009
Tarryall620231988
Gribbles Prk620241995
Wilson Creek520241990
Guffey520241995
Prospect Val519951995
Lay520241996
Nucla520241999
Cone Mtn420081988
Dinosaur420231995
Walsenburg420241994
Radium419991999
Mount Evans420241996
Mesaverde Np420241998
Yampa320231975

Rock Wren Population Trend in Other States

arizonacaliforniaidahokansasmontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexasutahwashingtonwyoming

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