BirdAnalyst
Species · Connecticut · BBS 2025 Release · 1966–2024

Common Merganser Population Trend in Connecticut

All statesWaterfowl

Common Merganser in Connecticut has edged down: down 15% on the route-weighted index since 1992.

-15%Since 1992TrendPercent 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 →
7Routes 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 →
16YearsYears 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 ConnecticutNotable 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 Connecticut. See the full index history below.

Common Merganser Survey Routes in Connecticut

Routes recording Common Merganser in Connecticut.
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 →
E Hartland219921988
New Hartford120021995
Sherman120132001
Long Hill120192018
Mid Haddam120112011
Southington120011992
Granby120212016

Common Merganser Population Trend in Other States

alaskaarizonacaliforniacoloradoidahomainemarylandmassachusettsmichiganminnesotamontananevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-dakotaohiooregonpennsylvaniasouth-dakotautahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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