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

Northern Rough-winged Swallow In Sierra Madre Occidental

All regionsSierra Madre OccidentalAerial insectivores

Northern Rough-winged Swallow in Sierra Madre Occidental has collapsed: down 86% on the route-weighted index since 1970.

-86%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 →
21Routes 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 →

Northern Rough-winged Swallow has collapsed in Sierra Madre Occidental: down 86% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Northern Rough-winged Swallow in Sierra Madre Occidental is projected to rise about 103% by 2029 — from 0.28 in 2024 to a central estimate of 0.56 (95% range 0.00–3.1). A 5-year backtest shows a typical error of ±246.7%, with 100% of held-out values landing inside the 95% band.

+103%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 →
0.56Projected 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 →
0.00–3.195% 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 →
±246.7%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, Northern Rough-winged Swallow in Sierra Madre Occidental is projected to rise about 103% by 2029 — from 0.28 in 2024 to a central estimate of 0.56 (95% range 0.00–3.1). A 5-year backtest shows a typical error of ±246.7%, 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 →
20250.630.003.2
20260.610.003.2
20270.600.003.2
20280.580.003.1
20290.560.003.1

Routes In Sierra Madre Occidental

Routes recording Northern Rough-winged 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 →
CutterARIZONA1682014
McnealARIZONA142017
Tonto Vill.ARIZONA52017
San SimonARIZONA41995
Peña BlancaARIZONA32000
Vicks PeakNEW-MEXICO31994
Mormon LakeARIZONA21974
BlueARIZONA21991
PomereneARIZONA22024
AlpineARIZONA22018
AmadoARIZONA22022
PrescottARIZONA12017
PatagoniaARIZONA12023
Skull ValleyARIZONA12022
Forest LakesARIZONA12024
Bartlett ResARIZONA12024
RedingtonARIZONA12023
Carr MtnARIZONA12024
SprucedaleARIZONA12012
Emory PassNEW-MEXICO12010
MagdalenaNEW-MEXICO12014

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