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

Swainson's Hawk Population Trend in Wyoming

All statesGeneralists

Swainson's Hawk in Wyoming has surged: up 171% on the route-weighted index since 1970.

+171%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 →
99Routes 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 →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Swainson's Hawk Trends in WyomingNotable 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 increasecomputed 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 →

Swainson's Hawk has surged in Wyoming: up 171% on the route-weighted index since 1970.

Swainson's Hawk Population Forecast in Wyoming

If the recent trend holds, Swainson's Hawk in Wyoming is projected to rise about 42% by 2029 — from 0.38 in 2024 to a central estimate of 0.54 (95% range 0.30–0.78). A 5-year backtest shows a typical error of ±15.3%, with 100% of held-out values landing inside the 95% band.

+42%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 →
0.54Projected 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 →
0.30–0.7895% 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 →
±15.3%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, Swainson's Hawk in Wyoming is projected to rise about 42% by 2029 — from 0.38 in 2024 to a central estimate of 0.54 (95% range 0.30–0.78). A 5-year backtest shows a typical error of ±15.3%, 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 →
20250.530.290.76
20260.530.290.77
20270.530.300.77
20280.540.300.77
20290.540.300.78

Swainson's Hawk Survey Routes in Wyoming

Routes recording Swainson's Hawk in Wyoming.
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 →
Harmony820231982
Elk Horn520181991
Clarkelen419781968
Seedskadee420161986
Ethete320231992
Highlight320071989
Newcastle320241988
Mtn View319801980
Cheyenne320241980
Chugwater320241982
Midvale220241998
Cumberland219801980
Mammoth219911985
Dayton220182008
Soda Well220231999
Riverview220161982
Boulder220241984
Gas Hills220121992
Pathfinder220241984
Walcott220241982
Rock River220161990
Pine Bluff220241983
Rozet220171993
Gvnt Valley220182002
Savageton220192019

Swainson's Hawk Population Trend in Other States

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