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

Mottled Duck In Gulf Coastal Prairie

All regionsGulf Coastal PrairieWaterfowl

Mottled Duck in Gulf Coastal Prairie has collapsed: down 81% on the route-weighted index since 1969.

-81%Since 1969TrendPercent 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 →
43Routes 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 →
57YearsYears 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 →

Mottled Duck has collapsed in Gulf Coastal Prairie: down 81% on the route-weighted index since 1969.

Mottled Duck In Gulf Coastal Prairie Population Forecast

If the recent trend holds, Mottled Duck in Gulf Coastal Prairie is projected to fall about 23% by 2029 — from 1.4 in 2024 to a central estimate of 1.1 (95% range 0.00–6.9). A 5-year backtest shows a typical error of ±35%, with 100% of held-out values landing inside the 95% band.

-23%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 →
1.1Projected 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 →
0.00–6.995% 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 →
±35%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, Mottled Duck in Gulf Coastal Prairie is projected to fall about 23% by 2029 — from 1.4 in 2024 to a central estimate of 1.1 (95% range 0.00–6.9). A 5-year backtest shows a typical error of ±35%, with 100% 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 →
20251.80.007.7
20261.60.007.5
20271.40.007.3
20281.30.007.1
20291.10.006.9

Routes In Gulf Coastal Prairie

Routes recording Mottled Duck 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 →
Bayside 2TEXAS512004
JuniorLOUISIANA321991
StowellTEXAS222018
Gran ChenierLOUISIANA201976
Ville PlatteLOUISIANA112019
Ltl Chenier 2LOUISIANA102011
Loyola BeachTEXAS102009
MauriceLOUISIANA72024
Grand IsleLOUISIANA72018
Forked Island 2LOUISIANA62011
Lag AtascosaTEXAS62023
LafitteLOUISIANA51991
CreoleLOUISIANA51987
EstherLOUISIANA52024
Sabine Nwr 2LOUISIANA52017
L. Atascosa NwrTEXAS52023
RichardLOUISIANA42023
Vinton 2LOUISIANA42023
GlencoeLOUISIANA32015
Ltl ChenierLOUISIANA32024
Sabine NwrLOUISIANA32001
Forked IslandLOUISIANA32024
Port AcresTEXAS32024
HackberryLOUISIANA22016
WoodlawnLOUISIANA22021

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