BirdAnalyst
Species · BCR 33 · BBS 2026 Release · 1966–2025

Northern Rough-winged Swallow In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsAerial insectivores

Northern Rough-winged Swallow in Sonoran and Mojave Deserts has risen sharply: up 65% on the route-weighted index since 1970.

+65%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 →
58Routes 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 →
57YearsYears 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 →

Northern Rough-winged Swallow has risen sharply in Sonoran and Mojave Deserts: up 65% on the route-weighted index since 1970.

Northern Rough-winged Swallow In Sonoran and Mojave Deserts Population Forecast

If the recent trend holds, Northern Rough-winged Swallow in Sonoran and Mojave Deserts is projected to fall about 94% by 2030 — from 2.5 in 2025 to a central estimate of 0.15 (95% range 0.00–12). A 5-year backtest shows a typical error of ±34%, with 100% of held-out values landing inside the 95% band.

-94%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 →
0.15Projected 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 →
0.00–1295% 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 →
±34%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 Sonoran and Mojave Deserts is projected to fall about 94% by 2030 — from 2.5 in 2025 to a central estimate of 0.15 (95% range 0.00–12). A 5-year backtest shows a typical error of ±34%, 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 →
20260.870.0013
20270.690.0013
20280.510.0013
20290.330.0013
20300.150.0012

Routes In Sonoran and Mojave Deserts

Routes recording Northern Rough-winged Swallow in Sonoran and Mojave Deserts.
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 →
Cutter 2ARIZONA1112018
BrawleyCALIFORNIA482010
DatelandARIZONA302025
Palo VerdeARIZONA202013
Parker DamCALIFORNIA182007
Cactus ForestARIZONA152021
Palo Verde 2ARIZONA152025
Coachella CnCALIFORNIA142013
BlytheCALIFORNIA141979
Red RockARIZONA102014
GlamisCALIFORNIA92018
Havasu LakeCALIFORNIA92003
NilandCALIFORNIA92025
Imperial DamCALIFORNIA92010
LagunaARIZONA82023
Palo VerdeCALIFORNIA82025
Cabeza PrietARIZONA52025
Organ PipeARIZONA42018
BarstowCALIFORNIA41998
Kelso ValleyCALIFORNIA42003
OatmanARIZONA32016
New RiverARIZONA32015
FlorenceARIZONA31988
HopeARIZONA32004
Calif CityCALIFORNIA32012

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