BirdAnalyst
Species · New York · BBS 2025 Release · 1966–2024

Common Merganser Population Trend in New York

All statesWaterfowl

Common Merganser in New York has surged: up 379% on the route-weighted index since 1969.

+379%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 →
61Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
53YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Common Merganser Trends in New YorkNotable 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 →

Common Merganser has surged in New York: up 379% on the route-weighted index since 1969.

Common Merganser Population Forecast in New York

If the recent trend holds, Common Merganser in New York is projected to rise about 216% by 2029 — from 0.08 in 2024 to a central estimate of 0.24 (95% range 0.07–0.42). A 5-year backtest shows a typical error of ±76.7%, with 100% of held-out values landing inside the 95% band.

+216%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 →
0.24Projected 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 →
0.07–0.4295% 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 →
±76.7%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 New York is projected to rise about 216% by 2029 — from 0.08 in 2024 to a central estimate of 0.24 (95% range 0.07–0.42). A 5-year backtest shows a typical error of ±76.7%, 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 →
20250.230.050.40
20260.230.060.41
20270.240.060.41
20280.240.070.41
20290.240.070.42

Common Merganser Survey Routes in New York

Routes recording Common Merganser in New York.
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 →
Harris Hill820192019
Lisle620072007
Austerlitz520072007
Oneonta520231998
North River420071987
Highland319971996
Macdougall320222001
Cobleskill220152015
Laurens220241997
Randolph220082008
Centerville220052005
Alder Creek220041989
Oneida220092004
Speculator220231966
Gabriels220131986
Sabattis219701970
S Vandalia220161990
Oxford 2120131993
Catskills120031999
Ghent120072006
Durham119711971
Medusa120211994
Meridale120242003
Duanesburg120182018
S Berne120112011

Common Merganser Population Trend in Other States

alaskaarizonacaliforniacoloradoconnecticutidahomainemarylandmassachusettsmichiganminnesotamontananevadanew-hampshirenew-jerseynew-mexiconorth-dakotaohiooregonpennsylvaniasouth-dakotautahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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