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

Purple Gallinule In Gulf Coastal Prairie

All regionsGulf Coastal PrairieWetland birds

Purple Gallinule in Gulf Coastal Prairie has risen sharply: up 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 →
27Routes 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 →
52YearsYears 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 →

Purple Gallinule has risen sharply in Gulf Coastal Prairie: up 56% on the route-weighted index since 1970.

Purple Gallinule In Gulf Coastal Prairie Population Forecast

If the recent trend holds, Purple Gallinule in Gulf Coastal Prairie is projected to fall about 66% by 2030 — from 1.3 in 2025 to a central estimate of 0.43 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±69.5%, with 100% of held-out values landing inside the 95% band.

-66%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 →
0.43Projected 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 →
0.00–1.995% 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 →
±69.5%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, Purple Gallinule in Gulf Coastal Prairie is projected to fall about 66% by 2030 — from 1.3 in 2025 to a central estimate of 0.43 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±69.5%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20260.440.001.9
20270.440.001.9
20280.430.001.9
20290.430.001.9
20300.430.001.9

Routes In Gulf Coastal Prairie

Routes recording Purple Gallinule 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 →
Ltl ChenierLOUISIANA152025
Forked IslandLOUISIANA72025
Forked Island 2LOUISIANA62010
MamouLOUISIANA41980
WinnieTEXAS32025
Hackberry 2LOUISIANA22018
ChinquapinTEXAS22006
Oyster LakeTEXAS22006
Port AcresTEXAS22025
Gran ChenierLOUISIANA11982
HackberryLOUISIANA11998
GlencoeLOUISIANA11989
EstherLOUISIANA12024
MauriceLOUISIANA11995
KaplanLOUISIANA12022
RichardLOUISIANA11998
Sabine NwrLOUISIANA12004
Sabine Nwr 2LOUISIANA12012
Hinkles FerTEXAS11992
IndianolaTEXAS12023
StowellTEXAS12005
DanburyTEXAS11981
KatyTEXAS12025
Rock IslandTEXAS12015
Moon LakeTEXAS12007

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