BirdAnalyst
Species · BCR 37 · BBS 2025 Release · 1966–2024

Cliff Swallow In Gulf Coastal Prairie

All regionsGulf Coastal PrairieAerial insectivores

Cliff Swallow in Gulf Coastal Prairie has surged: up 42× on the route-weighted index since 1980.

42×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 →
46YearsYears 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 42× 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 103% by 2029 — from 30 in 2024 to a central estimate of 61 (95% range 19–103). A 5-year backtest shows a typical error of ±111.7%, 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 →
61Projected 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 →
19–10395% 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 →
±111.7%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, Cliff Swallow in Gulf Coastal Prairie is projected to rise about 103% by 2029 — from 30 in 2024 to a central estimate of 61 (95% range 19–103). A 5-year backtest shows a typical error of ±111.7%, with 100% of held-out values landing inside the 95% band.19782029
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 →
2025571598
20265816100
20275917101
20286018102
20296119103

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
Bayside 2TEXAS1702004
Rock IslandTEXAS1202024
WoodlawnLOUISIANA1112021
WinnieTEXAS1112024
Forked IslandLOUISIANA1062024
Oyster LakeTEXAS982024
Hinkles FerTEXAS732024
Moon LakeTEXAS632011
PetronilaTEXAS502024
StowellTEXAS502023
Port AcresTEXAS372024
McfaddinTEXAS352016
Padre Island PaisTEXAS322015
Bayside 3TEXAS302023
DanburyTEXAS202024
Forked Island 2LOUISIANA192011
HackberryLOUISIANA182014
Hackberry 2LOUISIANA152018
KaplanLOUISIANA142023
BaysideTEXAS112010
RichardLOUISIANA82023
Lag AtascosaTEXAS62021
Moon Lake 2TEXAS62024
Ltl ChenierLOUISIANA52024

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