BirdAnalyst
Species · BCR 37 · BBS 2026 Release · 1966–2025

Cliff Swallow In Gulf Coastal Prairie

All regionsGulf Coastal PrairieAerial insectivores

Cliff Swallow in Gulf Coastal Prairie has surged: up 40× on the route-weighted index since 1980.

40×Since 1980TrendPercent 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 →
37Routes 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 →
47YearsYears 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 →

Cliff Swallow has surged in Gulf Coastal Prairie: up 40× on the route-weighted index since 1980.

Cliff Swallow In Gulf Coastal Prairie Population Forecast

If the recent trend holds, Cliff Swallow in Gulf Coastal Prairie is projected to rise about 128% by 2030 — from 26 in 2025 to a central estimate of 59 (95% range 17–101). A 5-year backtest shows a typical error of ±118.5%, with 80% of held-out values landing inside the 95% band.

+128%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 →
59Projected 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 →
17–10195% 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 →
±118.5%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, Cliff Swallow in Gulf Coastal Prairie is projected to rise about 128% by 2030 — from 26 in 2025 to a central estimate of 59 (95% range 17–101). A 5-year backtest shows a typical error of ±118.5%, with 80% of held-out values landing inside the 95% band.19782030
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 →
2026551397
2027561498
2028571599
20295816100
20305917101

Routes In Gulf Coastal Prairie

Routes recording Cliff Swallow in Gulf Coastal Prairie.
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 →
Goliad PrairieTEXAS5772016
Rock IslandTEXAS2272025
Bayside 2TEXAS1702004
WoodlawnLOUISIANA1112021
Moon LakeTEXAS632011
RichardLOUISIANA622025
PetronilaTEXAS502025
Hinkles FerTEXAS482025
EstherLOUISIANA412025
Forked IslandLOUISIANA412025
McfaddinTEXAS352016
ChinquapinTEXAS322025
Padre Island PaisTEXAS322015
Forked Island 2LOUISIANA192011
Port AcresTEXAS192025
HackberryLOUISIANA182014
Oyster LakeTEXAS182025
Hackberry 2LOUISIANA152018
KaplanLOUISIANA142023
BaysideTEXAS112010
WinnieTEXAS82025
Ltl ChenierLOUISIANA62025
Lag AtascosaTEXAS62021
Ltl Chenier 2LOUISIANA52011
StowellTEXAS52025

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