BirdAnalyst
Species · BCR 35 · BBS 2026 Release · 1966–2025

Violet-green Swallow In Chihuahuan Desert

All regionsChihuahuan DesertAerial insectivores

Violet-green Swallow in Chihuahuan Desert has surged: up 211% on the route-weighted index since 1975.

+211%Since 1975TrendPercent 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 →
22Routes 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 →
48YearsYears 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 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 →

Violet-green Swallow has surged in Chihuahuan Desert: up 211% on the route-weighted index since 1975.

Violet-green Swallow In Chihuahuan Desert Population Forecast

If the recent trend holds, Violet-green Swallow in Chihuahuan Desert is projected to fall about 85% by 2030 — from 4.0 in 2025 to a central estimate of 0.59 (95% range 0.00–7.7). A 5-year backtest shows a typical error of ±39.3%, with 100% of held-out values landing inside the 95% band.

-85%Change by 2030TrendPercent 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 →
0.59Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–7.795% 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 →
±39.3%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, Violet-green Swallow in Chihuahuan Desert is projected to fall about 85% by 2030 — from 4.0 in 2025 to a central estimate of 0.59 (95% range 0.00–7.7). A 5-year backtest shows a typical error of ±39.3%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20260.840.007.9
20270.780.007.9
20280.720.007.8
20290.650.007.7
20300.590.007.7

Routes In Chihuahuan Desert

Routes recording Violet-green Swallow in Chihuahuan Desert.
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 →
Red RockNEW-MEXICO1052025
CloudcroftNEW-MEXICO232025
ColumbusNEW-MEXICO102025
CarrizozoNEW-MEXICO42025
Capitan Mtn.NEW-MEXICO32015
Hot SpringsTEXAS32000
GageNEW-MEXICO22025
LaborcitaNEW-MEXICO22005
PinonNEW-MEXICO22017
MarfaTEXAS22005
Ft. DavisTEXAS22021
DemingNEW-MEXICO11974
JornadaNEW-MEXICO12002
QueenNEW-MEXICO12010
Hatchet PeakNEW-MEXICO12011
AltudaTEXAS11994
ValentineTEXAS11980
Delaware CrkTEXAS12014
CornudasTEXAS11968
SlaughterTEXAS11976
Bear MtnTEXAS12025
Salt FlatTEXAS12009

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.