BirdAnalyst
Species · BCR 34 · BBS 2025 Release · 1966–2024

Violet-green Swallow In Sierra Madre Occidental

All regionsSierra Madre OccidentalAerial insectivores

Violet-green Swallow in Sierra Madre Occidental has edged up: up 23% on the route-weighted index since 1970.

+23%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 →
32Routes 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 →
54YearsYears 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 →

No notable trend signals for Violet-green Swallow in Sierra Madre Occidental. See the full index history below.

Violet-green Swallow In Sierra Madre Occidental Population Forecast

If the recent trend holds, Violet-green Swallow in Sierra Madre Occidental is projected to fall about 26% by 2029 — from 8.6 in 2024 to a central estimate of 6.4 (95% range 1.8–11). A 5-year backtest shows a typical error of ±23.8%, with 100% of held-out values landing inside the 95% band.

-26%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 →
6.4Projected 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 →
1.8–1195% 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 →
±23.8%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 Sierra Madre Occidental is projected to fall about 26% by 2029 — from 8.6 in 2024 to a central estimate of 6.4 (95% range 1.8–11). A 5-year backtest shows a typical error of ±23.8%, 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 →
20256.51.911
20266.51.911
20276.51.911
20286.41.911
20296.41.811

Routes In Sierra Madre Occidental

Routes recording Violet-green Swallow in Sierra Madre Occidental.
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 →
Happy JackARIZONA1022024
AlpineARIZONA652023
Bartlett ResARIZONA302017
Forest LakesARIZONA282024
RuckerARIZONA272001
BlueARIZONA251991
PinetopARIZONA252022
Aztec PeakARIZONA231978
SprucedaleARIZONA222023
WilliamsARIZONA202019
MaineARIZONA162024
Mormon LakeARIZONA131975
FlagstaffARIZONA92022
PrescottARIZONA72022
Emory PassNEW-MEXICO72024
San SimonARIZONA61982
SunizonaARIZONA61996
Clay SpringARIZONA52009
Mt. GrahamARIZONA42023
Peña BlancaARIZONA32021
Tonto Vill.ARIZONA32021
RedingtonARIZONA32021
Carr MtnARIZONA22010
DragoonARIZONA22009
ReserveNEW-MEXICO22023

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