BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Tricolored Blackbird

IcteridaeWetland birdsAgelaius tricolor

Tricolored Blackbird has fallen sharply: down 53% on the route-weighted index since 1970.

-53%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 →
97RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56Years 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 Tricolored Blackbird

The Tricolored Blackbird (Agelaius tricolor) is a North American member of the Blackbirds & Orioles (Icteridae). In this analysis it is grouped with the wetland birds.

Size
6.5–17 in long (16–43 cm) — a small to medium songbird (typical for the family)
Habitat
Marshes, ponds, lakeshores and other freshwater wetlands.
Diet
Aquatic invertebrates, small fish, frogs and plant matter.
Range
Recorded on 97 Breeding Bird Survey routes across 3 states, most concentrated in the Coastal California.
Family
Icteridae · Wetland birds

Notable Tricolored Blackbird TrendsNotable 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 declinecomputed 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 →

Tricolored Blackbird has fallen sharply in surveyed states: down 53% on the route-weighted index since 1970.

Tricolored Blackbird Population Forecast

If the recent trend holds, Tricolored Blackbird is projected to fall about 62% by 2029 — from 0.22 in 2024 to a central estimate of 0.09 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±270.7%, with 100% of held-out values landing inside the 95% band.

-62%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 →
0.09Projected 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 →
0.00–1.995% 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 →
±270.7%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, Tricolored Blackbird is projected to fall about 62% by 2029 — from 0.22 in 2024 to a central estimate of 0.09 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±270.7%, 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 →
20250.180.002.0
20260.160.001.9
20270.130.001.9
20280.110.001.9
20290.090.001.9

Where the Tricolored Blackbird Is Detected

BBS routes recording Tricolored Blackbird, sized by most recent count.

Tricolored Blackbird Population Trend by State

Tricolored Blackbird 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 →
California-58%197089
Oregon-87%19727
Washingtoninsufficient datan/a1

Tricolored Blackbird Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Tricolored Blackbird 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 →
Northern Pacific Rainforest-7%19757
Great Basin-86%197214
Coastal California-48%197070
Sonoran and Mojave Deserts-88%19724

Tricolored Blackbird Conservation Status

Our route-weighted index shows it down about 53% since 1970.

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