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

Hooded Merganser Population Trend in Connecticut

All statesWaterfowl

Hooded Merganser in Connecticut has collapsed: down 82% on the route-weighted index since 1983.

-82%Since 1983TrendPercent 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 →
5Routes 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 →
13YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Hooded 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 →

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 →

Hooded Merganser has collapsed in Connecticut: down 82% on the route-weighted index since 1983.

Hooded Merganser Survey Routes in Connecticut

Routes recording Hooded 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 →
Buckingham120112011
No Woodbury120031983
Danbury119691968
Warren120061995
Mid Haddam120222007

Hooded Merganser Population Trend in Other States

alabamaalaskaarkansascoloradoidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-yorknorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontwashingtonwest-virginiawisconsinwyoming

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