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

American Kestrel In Coastal California

All regionsCoastal CaliforniaGeneralists

American Kestrel in Coastal California has collapsed: down 76% on the route-weighted index since 1970.

-76%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 →
118Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 →

American Kestrel has collapsed in Coastal California: down 76% on the route-weighted index since 1970.

American Kestrel In Coastal California Population Forecast

If the recent trend holds, American Kestrel in Coastal California is projected to fall about 62% by 2029 — from 2.0 in 2024 to a central estimate of 0.76 (95% range 0.00–2.6). A 5-year backtest shows a typical error of ±20.2%, 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 →
0.76Projected 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 →
0.00–2.695% 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 →
±20.2%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, American Kestrel in Coastal California is projected to fall about 62% by 2029 — from 2.0 in 2024 to a central estimate of 0.76 (95% range 0.00–2.6). A 5-year backtest shows a typical error of ±20.2%, 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 →
20250.980.002.8
20260.930.002.8
20270.870.002.7
20280.820.002.7
20290.760.002.6

Routes In Coastal California

Routes recording American Kestrel in Coastal California.
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 →
Tres Pinos 2CALIFORNIA262011
MorenoCALIFORNIA112024
RiovistaCALIFORNIA92024
HollisterCALIFORNIA62011
Yolla BollyCALIFORNIA62024
CoyoteCALIFORNIA62024
South LakeCALIFORNIA62006
Tracy 2CALIFORNIA62024
Tres PinosCALIFORNIA52003
ZamoraCALIFORNIA52024
TracyCALIFORNIA52009
Yokohl ValCALIFORNIA41997
Orange CoveCALIFORNIA42016
Lake BerryessaCALIFORNIA42024
Elsinore MtnCALIFORNIA42024
White RiverCALIFORNIA41992
LockwoodCALIFORNIA42024
LivermoreCALIFORNIA41991
AthloneCALIFORNIA42007
JofeganCALIFORNIA42022
CollegevilleCALIFORNIA32004
CaruthersCALIFORNIA31987
GravesboroCALIFORNIA31995
ParkfieldCALIFORNIA32024
SangerCALIFORNIA32024

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