Species · BCR 35 · BBS 2025 Release · 1966–2024

Vesper Sparrow In Chihuahuan Desert

Vesper Sparrow in Chihuahuan Desert has collapsed: down 93% on the route-weighted index since 1980.

-93%Since 1980
3Routes In Region
34Years

Notable Signals

long arc declinecomputed index

Vesper Sparrow has collapsed in Chihuahuan Desert: down 93% on the route-weighted index since 1980.

Forecast

If the recent trend holds, Vesper Sparrow in Chihuahuan Desert is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.53). A 5-year backtest shows a typical error of ±581.9%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2029
0.00Projected 2029 index
0.000.5395% range
±581.9%Backtest error
19772029
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
20250.000.000.53
20260.000.000.53
20270.000.000.53
20280.000.000.53
20290.000.000.53

Routes In Chihuahuan Desert

Routes recording Vesper Sparrow in Chihuahuan Desert.
CarrizozoNEW-MEXICO22021
Capitan Mtn.NEW-MEXICO12017
PinonNEW-MEXICO12024

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