BirdAnalyst
Species · BCR 15 · BBS 2025 Release · 1966–2024

Violet-green Swallow In Sierra Nevada

All regionsSierra NevadaAerial insectivores

Violet-green Swallow in Sierra Nevada has collapsed: down 81% on the route-weighted index since 1972.

-81%Since 1972
29Routes In Region
54Years

Notable Signals

long arc declinecomputed index

Violet-green Swallow has collapsed in Sierra Nevada: down 81% on the route-weighted index since 1972.

Forecast

If the recent trend holds, Violet-green Swallow in Sierra Nevada is projected to fall about 100% by 2029 — from 1.1 in 2024 to a central estimate of 0.00 (95% range 0.00–2.9). A 5-year backtest shows a typical error of ±60.1%, with 100% of held-out values landing inside the 95% band.

-100%Change by 2029
0.00Projected 2029 index
0.00–2.995% range
±60.1%Backtest error
19692029
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
20250.210.003.1
20260.130.003.1
20270.060.003.0
20280.000.002.9
20290.000.002.9

Routes In Sierra Nevada

Routes recording Violet-green Swallow in Sierra Nevada.
Forest Hill 2CALIFORNIA112005
SattleyCALIFORNIA61994
PaxtonCALIFORNIA62024
WoodfordsCALIFORNIA52024
ChilcootCALIFORNIA52024
WestvilleCALIFORNIA42022
Bass LakeCALIFORNIA42019
Silver CityCALIFORNIA42013
Kings CanyonCALIFORNIA42024
Lassen ParkCALIFORNIA21986
DownievilleCALIFORNIA21996
Hat CreekCALIFORNIA22007
Forest HillCALIFORNIA22021
Pine MountainCALIFORNIA22017
Eagle LakeCALIFORNIA12018
Cottage SpgsCALIFORNIA11975
DardanelleCALIFORNIA12014
Greenhorn MtCALIFORNIA12008
Tuolumne GroveCALIFORNIA12024
Butte MeadowCALIFORNIA11988
GeneseeCALIFORNIA12019
Higgins CornCALIFORNIA11991
RivertonCALIFORNIA11992
LakeshoreCALIFORNIA12002
GoumazCALIFORNIA12002

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