BirdAnalyst
Species · BCR 36 · BBS 2025 Release · 1966–2024

Northern Rough-winged Swallow In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsAerial insectivores

Northern Rough-winged Swallow in Tamaulipan Brushlands has fallen sharply: down 56% on the route-weighted index since 1970.

-56%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 →
20Routes 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 →
40YearsYears 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 Tamaulipan Brushlands: down 56% on the route-weighted index since 1970.

Northern Rough-winged Swallow In Tamaulipan Brushlands Population Forecast

If the recent trend holds, Northern Rough-winged Swallow in Tamaulipan Brushlands is projected to rise about 659% by 2029 — from 0.17 in 2024 to a central estimate of 1.3 (95% range 0.00–7.2). A 5-year backtest shows a typical error of ±468.2%, with 80% of held-out values landing inside the 95% band.

+659%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 →
1.3Projected 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 →
0.00–7.295% 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 →
±468.2%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 Tamaulipan Brushlands is projected to rise about 659% by 2029 — from 0.17 in 2024 to a central estimate of 1.3 (95% range 0.00–7.2). A 5-year backtest shows a typical error of ±468.2%, with 80% of held-out values landing inside the 95% band.19672029
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 →
20251.30.007.3
20261.30.007.3
20271.30.007.3
20281.30.007.2
20291.30.007.2

Routes In Tamaulipan Brushlands

Routes recording Northern Rough-winged Swallow in Tamaulipan Brushlands.
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 →
ZapataTEXAS311987
Pedro CreekTEXAS72005
George WestTEXAS61974
CatarinaTEXAS61975
El IndioTEXAS42000
SejitaTEXAS42015
LaredoTEXAS42018
La PryorTEXAS32010
Agua NuevaTEXAS22014
KingsvilleTEXAS22024
Mirando CityTEXAS22014
HondoTEXAS22003
GuerraTEXAS22010
ProgresoTEXAS22008
RachalTEXAS12023
RandadoTEXAS12013
RaymondvilleTEXAS11994
Encinal 2TEXAS12023
MillettTEXAS11998
HeidelbergTEXAS12023

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