BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Gyrfalcon

FalconidaeBirds of preyFalco rusticolus

Gyrfalcon has declined: down 43% on the route-weighted index since 1994.

-43%Since 1994TrendPercent 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 →
12RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
22Years 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 Gyrfalcon

The Gyrfalcon (Falco rusticolus) is a North American member of the Falcons & Caracaras (Falconidae). In this analysis it is grouped with the birds of prey.

Size
10–23.5 in long (25–60 cm) — a streamlined raptor (typical for the family)
Habitat
Open country, woodlands, cliffs and wetlands, hunting from the air or a high perch.
Diet
Live prey — small mammals, birds, reptiles, fish and large insects (carrion for vultures).
Range
Recorded on 12 Breeding Bird Survey routes across 1 state, most concentrated in the BCR 2.
Family
Falconidae · Birds of prey

Notable Gyrfalcon 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 Gyrfalcon. See the full index history below.

Gyrfalcon Population Forecast

If the recent trend holds, Gyrfalcon is projected to stay roughly flat through 2027, near 0.00 (95% range 0.00–0.00). A 5-year backtest shows a typical error of ±43.4%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2027TrendPercent 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 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0095% 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 →
±43.4%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, Gyrfalcon is projected to stay roughly flat through 2027, near 0.00 (95% range 0.00–0.00). A 5-year backtest shows a typical error of ±43.4%, with 100% of held-out values landing inside the 95% band.19832027
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 →
20230.000.000.00
20240.000.000.00
20250.000.000.00
20260.000.000.00
20270.000.000.00

Where the Gyrfalcon Is Detected

BBS routes recording Gyrfalcon, sized by most recent count.

Gyrfalcon Population Trend by State

Gyrfalcon 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-57%199412

Gyrfalcon Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Gyrfalcon 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 2+110%19956

Gyrfalcon Conservation Status

Our route-weighted index shows it down about 43% since 1994.

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