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Species · Colorado · BBS 2025 Release · 1966–2024

Hammond's Flycatcher Population Trend in Colorado

All statesAerial insectivores

Hammond's Flycatcher in Colorado has surged: up 390% on the route-weighted index since 1974.

+390%Since 1974TrendPercent 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 →
69Routes 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 →
45YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Hammond's Flycatcher 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 →

Hammond's Flycatcher has surged in Colorado: up 390% on the route-weighted index since 1974.

Hammond's Flycatcher Population Forecast in Colorado

If the recent trend holds, Hammond's Flycatcher in Colorado is projected to rise about 33% by 2029 — from 0.43 in 2024 to a central estimate of 0.58 (95% range 0.12–1.0). A 5-year backtest shows a typical error of ±145.3%, with 80% of held-out values landing inside the 95% band.

+33%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 →
0.58Projected 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 →
0.12–1.095% 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 →
±145.3%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, Hammond's Flycatcher in Colorado is projected to rise about 33% by 2029 — from 0.43 in 2024 to a central estimate of 0.58 (95% range 0.12–1.0). A 5-year backtest shows a typical error of ±145.3%, with 80% of held-out values landing inside the 95% band.19692029
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 →
20250.560.101.0
20260.560.111.0
20270.570.111.0
20280.570.121.0
20290.580.121.0

Hammond's Flycatcher Survey Routes in Colorado

Routes recording Hammond's Flycatcher 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 →
Dolores Riv820241993
Kiowa620012001
Haycamp Mesa620242001
Lost Lake520241993
Comanche Pk420241996
Cheesman Lk320211988
Summitville320001994
Steamboat L.320242024
Lake City320031998
Marshall Pas320101995
Guanella Pas320182001
Tincup320072007
Stillwater Pass320092002
Lizard Head Pass320242002
Yampa220082008
Harmony220172014
Mesaverde Np220072001
Douglas Pass220241987
Rio Grnds Rs220021993
Tarryall220191995
Powderhorn220232004
Gold Hill 2220242018
Wet Mtns.219931993
Radium219981998
Mount Evans120181997

Hammond's Flycatcher Population Trend in Other States

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