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

Northern Rough-winged Swallow In Chihuahuan Desert

All regionsChihuahuan DesertAerial insectivores

Northern Rough-winged Swallow in Chihuahuan Desert has fallen sharply: down 68% on the route-weighted index since 1977.

-68%Since 1977TrendPercent 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 →
33Routes 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 →
39YearsYears 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 fallen sharply in Chihuahuan Desert: down 68% on the route-weighted index since 1977.

Northern Rough-winged Swallow In Chihuahuan Desert Population Forecast

If the recent trend holds, Northern Rough-winged Swallow in Chihuahuan Desert is projected to fall about 39% by 2029 — from 0.24 in 2024 to a central estimate of 0.15 (95% range 0.00–0.86). A 5-year backtest shows a typical error of ±167.8%, with 100% of held-out values landing inside the 95% band.

-39%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 →
0.15Projected 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 →
0.00–0.8695% 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 →
±167.8%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, Northern Rough-winged Swallow in Chihuahuan Desert is projected to fall about 39% by 2029 — from 0.24 in 2024 to a central estimate of 0.15 (95% range 0.00–0.86). A 5-year backtest shows a typical error of ±167.8%, with 100% of held-out values landing inside the 95% band.19742029
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 →
20250.210.000.93
20260.190.000.91
20270.180.000.90
20280.160.000.88
20290.150.000.86

Routes In Chihuahuan Desert

Routes recording Northern Rough-winged 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 →
Black GapTEXAS122019
RoswellNEW-MEXICO72023
OzonaTEXAS72014
Red RockNEW-MEXICO52022
PinonNEW-MEXICO32024
Devils R CynTEXAS32011
CanutilloTEXAS32024
San AntonioNEW-MEXICO21977
CarrizozoNEW-MEXICO22008
MesillaNEW-MEXICO22000
Lake ValleyNEW-MEXICO22004
PresidioTEXAS22006
Quitman Cyn.TEXAS22009
GageNEW-MEXICO12009
DemingNEW-MEXICO11974
JornadaNEW-MEXICO12014
CloudcroftNEW-MEXICO12011
RodeoNEW-MEXICO12011
LaborcitaNEW-MEXICO12018
Bitter LakeNEW-MEXICO12022
ColumbusNEW-MEXICO12006
EscondidaNEW-MEXICO12007
Laborcita 2NEW-MEXICO12024
ComstockTEXAS12022
Hot SpringsTEXAS12000

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