BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Horned Grebe

PodicipedidaeWetland birdsPodiceps auritus

Horned Grebe has declined: down 40% on the route-weighted index since 1971.

-40%Since 1971TrendPercent 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 →
55RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
49Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Horned Grebe

The Horned Grebe (Podiceps auritus) is a North American member of the Grebes (Podicipedidae). In this analysis it is grouped with the wetland birds.

Size
9–21.5 in long (23–55 cm) — a diving water bird (typical for the family)
Habitat
Marshes, ponds, lakeshores and other freshwater wetlands.
Diet
Aquatic invertebrates, small fish, frogs and plant matter.
Range
Recorded on 55 Breeding Bird Survey routes across 8 states, most concentrated in the Prairie Potholes.
Family
Podicipedidae · Wetland birds

Notable Horned Grebe TrendsNotable 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 Horned Grebe. See the full index history below.

Horned Grebe Population Forecast

If the recent trend holds, Horned Grebe is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.01). A 5-year backtest shows a typical error of ±223%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00Projected 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 →
0.00–0.0195% 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 →
±223%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, Horned Grebe is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.01). A 5-year backtest shows a typical error of ±223%, 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 →
20250.000.000.01
20260.000.000.01
20270.000.000.01
20280.000.000.01
20290.000.000.01

Where the Horned Grebe Is Detected

BBS routes recording Horned Grebe, sized by most recent count.

Horned Grebe Population Trend by State

Horned Grebe population trend by state.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Alaska-84%198724
Minnesotainsufficient datan/a1
Montanainsufficient datan/a4
North Dakota-32%197119
South Dakotainsufficient datan/a3
Washingtoninsufficient datan/a1
Wisconsininsufficient datan/a1
Wyominginsufficient datan/a2

Horned Grebe Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Horned Grebe population trend by Bird Conservation Region.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
BCR 4-89%198717
Northern Pacific Rainforest-37%19953
Prairie Potholes-48%197124

Horned Grebe Conservation Status

Our route-weighted index shows it down about 40% since 1971.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.