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

Eared Grebe Population Trend in Colorado

All statesWetland birds

Eared Grebe in Colorado has edged up: up 15% on the route-weighted index since 1980.

+15%Since 1980TrendPercent 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 →
21Routes 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 →
34YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Eared Grebe 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 →

No notable trend signals for Eared Grebe in Colorado. See the full index history below.

Eared Grebe Population Forecast in Colorado

If the recent trend holds, Eared Grebe in Colorado is projected to fall about 11% by 2029 — from 0.19 in 2024 to a central estimate of 0.17 (95% range 0.00–0.35). A 5-year backtest shows a typical error of ±46.9%, with 100% of held-out values landing inside the 95% band.

-11%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 →
0.17Projected 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 →
0.00–0.3595% 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 →
±46.9%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, Eared Grebe in Colorado is projected to fall about 11% by 2029 — from 0.19 in 2024 to a central estimate of 0.17 (95% range 0.00–0.35). A 5-year backtest shows a typical error of ±46.9%, 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 →
20250.160.000.35
20260.160.000.35
20270.160.000.35
20280.160.000.35
20290.170.000.35

Eared Grebe Survey Routes in Colorado

Routes recording Eared Grebe 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 →
Wildhorse L3020152015
Alamosa2420232023
Dinosaur1220241995
Rio Grnds Rs620241994
Kiowa519991980
Mcphee Res.520191997
Guffey420172015
Haswell320222022
Walden220161991
Willow Peak220092009
Tarryall220182013
Nunn220192019
Amherst220072007
Cortez219981998
Dolores119841968
Falfa119801980
Pagosa Spgs119751975
Cortez 2120162010
Doyleville119891989
Julesburg120112007
Piedra120122012

Eared Grebe Population Trend in Other States

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