BirdAnalyst
Species · BCR 32 · BBS 2025 Release · 1966–2024

Swainson's Hawk In Coastal California

All regionsCoastal CaliforniaGeneralists

Swainson's Hawk in Coastal California has surged: up 27× on the route-weighted index since 1975.

27×Since 1975
25Routes In Region
49Years

Notable Signals

long arc increasecomputed index

Swainson's Hawk has surged in Coastal California: up 27× on the route-weighted index since 1975.

Forecast

If the recent trend holds, Swainson's Hawk in Coastal California is projected to rise about 11% by 2029 — from 1.6 in 2024 to a central estimate of 1.8 (95% range 0.11–3.4). A 5-year backtest shows a typical error of ±78.3%, with 100% of held-out values landing inside the 95% band.

+11%Change by 2029
1.8Projected 2029 index
0.11–3.495% range
±78.3%Backtest error
19722029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20251.60.003.3
20261.70.003.3
20271.70.033.4
20281.70.073.4
20291.80.113.4

Routes In Coastal California

Routes recording Swainson's Hawk in Coastal California.
Collegeville 2CALIFORNIA422023
Ora LomaCALIFORNIA292024
AthloneCALIFORNIA242007
AtwaterCALIFORNIA142012
WestleyCALIFORNIA132024
ZamoraCALIFORNIA102024
Staten Is.CALIFORNIA92024
Buena VistaCALIFORNIA82019
Tracy 2CALIFORNIA62024
CollegevilleCALIFORNIA22004
HughsonCALIFORNIA22024
TranquillityCALIFORNIA22024
TracyCALIFORNIA22009
PenningtonCALIFORNIA12023
RiovistaCALIFORNIA12022
CohassetCALIFORNIA12024
OrlandCALIFORNIA12017
SangerCALIFORNIA12015
Carrizo PlnCALIFORNIA12022
GlennCALIFORNIA12009
CordovaCALIFORNIA11975
OrovilleCALIFORNIA12024
CoyoteCALIFORNIA12019
OnealsCALIFORNIA12024
PolomaCALIFORNIA12024

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