BirdAnalyst
Species · BCR 22 · BBS 2025 Release · 1966–2024

Blue-winged Teal In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieWaterfowl

Blue-winged Teal in Eastern Tallgrass Prairie has fallen sharply: down 63% on the route-weighted index since 1968.

-63%Since 1968TrendPercent 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 →
83Routes 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 →

Blue-winged Teal has fallen sharply in Eastern Tallgrass Prairie: down 63% on the route-weighted index since 1968.

Blue-winged Teal In Eastern Tallgrass Prairie Population Forecast

If the recent trend holds, Blue-winged Teal in Eastern Tallgrass Prairie is projected to fall about 85% by 2029 — from 0.11 in 2024 to a central estimate of 0.02 (95% range 0.00–0.21). A 5-year backtest shows a typical error of ±61.1%, with 100% of held-out values landing inside the 95% band.

-85%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 →
0.02Projected 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 →
0.00–0.2195% 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 →
±61.1%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, Blue-winged Teal in Eastern Tallgrass Prairie is projected to fall about 85% by 2029 — from 0.11 in 2024 to a central estimate of 0.02 (95% range 0.00–0.21). A 5-year backtest shows a typical error of ±61.1%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.030.000.22
20260.020.000.22
20270.020.000.22
20280.020.000.21
20290.020.000.21

Routes In Eastern Tallgrass Prairie

Routes recording Blue-winged Teal in Eastern Tallgrass 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 →
Sioux CityIOWA132024
CubaOHIO111996
ItascaILLINOIS101973
BelleviewILLINOIS81988
MelroseILLINOIS61990
Trading PostKANSAS52014
BrookvilleINDIANA41997
GalesburgKANSAS42014
GeneseoILLINOIS31975
EssexILLINOIS31979
NewarkILLINOIS31975
New LenoxILLINOIS31981
OlneyILLINOIS32013
Cedar ValleyIOWA31973
DesmoinesIOWA31979
Rock ValleyIOWA31988
GretnaNEBRASKA32016
SheffieldILLINOIS21974
ComptonILLINOIS21972
StillwellILLINOIS21992
ChandlervillILLINOIS21995
Terre HauteILLINOIS22004
BartonvilleILLINOIS21973
PawneeILLINOIS22002
KeithsburgILLINOIS22002

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