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

Fulvous Whistling-Duck In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsWaterfowl

Fulvous Whistling-Duck in Tamaulipan Brushlands has edged down: down 23% on the route-weighted index since 1971.

-23%Since 1971TrendPercent 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 →
6Routes 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 →

No notable trend signals for Fulvous Whistling-Duck in Tamaulipan Brushlands. See the full index history below.

Fulvous Whistling-Duck In Tamaulipan Brushlands Population Forecast

If the recent trend holds, Fulvous Whistling-Duck in Tamaulipan Brushlands is projected to rise about 536% by 2029 — from 0.33 in 2024 to a central estimate of 2.1 (95% range 0.00–8.4). A 5-year backtest shows a typical error of ±200.5%, with 100% of held-out values landing inside the 95% band.

+536%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 →
2.1Projected 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 →
0.00–8.495% 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 →
±200.5%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, Fulvous Whistling-Duck in Tamaulipan Brushlands is projected to rise about 536% by 2029 — from 0.33 in 2024 to a central estimate of 2.1 (95% range 0.00–8.4). A 5-year backtest shows a typical error of ±200.5%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20252.10.008.3
20262.10.008.4
20272.10.008.4
20282.10.008.4
20292.10.008.4

Routes In Tamaulipan Brushlands

Routes recording Fulvous Whistling-Duck 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 →
ProgresoTEXAS242008
HeidelbergTEXAS212023
KingsvilleTEXAS82019
RaymondvilleTEXAS42024
SejitaTEXAS32021
GuerraTEXAS21988

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