BirdAnalyst
Species · BCR 17 · BBS 2025 Release · 1966–2024

Common Merganser In Badlands and Prairies

All regionsBadlands and PrairiesWaterfowl

Common Merganser in Badlands and Prairies has edged up: up 12% on the route-weighted index since 1979.

+12%Since 1979TrendPercent 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 →
23Routes 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 →
34YearsYears 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 Common Merganser in Badlands and Prairies. See the full index history below.

Common Merganser In Badlands and Prairies Population Forecast

If the recent trend holds, Common Merganser in Badlands and Prairies is projected to fall about 47% by 2029 — from 0.09 in 2024 to a central estimate of 0.05 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±55.5%, with 100% of held-out values landing inside the 95% band.

-47%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 →
0.05Projected 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 →
0.00–0.1395% 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 →
±55.5%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, Common Merganser in Badlands and Prairies is projected to fall about 47% by 2029 — from 0.09 in 2024 to a central estimate of 0.05 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±55.5%, with 100% of held-out values landing inside the 95% band.19762029
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 →
20250.050.000.13
20260.050.000.13
20270.050.000.13
20280.050.000.13
20290.050.000.13

Routes In Badlands and Prairies

Routes recording Common Merganser in Badlands and Prairies.
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 →
FlatwillowMONTANA41977
Caballa CrkWYOMING42008
Maynard CouleeMONTANA32022
MayoworthWYOMING32010
Seely 2WYOMING32008
CircleMONTANA22000
Two DotMONTANA22024
St Xavier 2MONTANA22018
Wheat BasinMONTANA22019
VolunteerSOUTH-DAKOTA21983
DwyerWYOMING21992
ArvadaWYOMING22024
SeelyWYOMING21994
SussexWYOMING22023
HighwoodMONTANA12024
BrusettMONTANA11985
ShawmutMONTANA12005
Reed PointMONTANA12024
RochfordSOUTH-DAKOTA11995
NatronaWYOMING11990
DaytonWYOMING12022
SchoonoverWYOMING11995
WelchWYOMING12017

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