BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Least Grebe

PodicipedidaeWetland birdsTachybaptus dominicus

Least Grebe has surged: up 115% on the route-weighted index since 1972.

+115%Since 1972TrendPercent 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 →
24RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
26Years 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 Least Grebe

The Least Grebe (Tachybaptus dominicus) 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 24 Breeding Bird Survey routes across 1 state, most concentrated in the Tamaulipan Brushlands.
Family
Podicipedidae · Wetland birds

Notable Least 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 Least Grebe. See the full index history below.

Least Grebe Population Forecast

If the recent trend holds, Least Grebe is projected to stay roughly flat through 2028, near 0.00 (95% range 0.00–0.01). A 5-year backtest shows a typical error of ±186%, with 80% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 2028 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 →
±186%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, Least Grebe is projected to stay roughly flat through 2028, near 0.00 (95% range 0.00–0.01). A 5-year backtest shows a typical error of ±186%, with 80% of held-out values landing inside the 95% band.19672028
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 →
20240.000.000.01
20250.000.000.01
20260.000.000.01
20270.000.000.01
20280.000.000.01

Where the Least Grebe Is Detected

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

Least Grebe Population Trend by State

Least 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 →
Texas+87%197224

Least Grebe Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Least 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 →
Tamaulipan Brushlands-72%197211
Gulf Coastal Prairie+247%20009

Least Grebe Conservation Status

Our route-weighted index shows it up about 115% since 1972.

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