Birds

Common Merganser

Mergus merganser · Ferestraș mare

A large, streamlined fish-eating duck that breeds locally on Carpathian reservoirs and rivers and spreads to large lakes and rivers in winter.

At a glance

Status in Romania: Resident
Habitat: Wetland / Mountain / Forest
Activity: Morning · Daytime · Evening
Diet: Mainly small fish, plus aquatic invertebrates, amphibians, small mammals and birds; only small amounts of plant matter.
Conservation status: Least Concern (IUCN)
Photography difficulty: Moderate

Photograph this species

Best months: All year
Best time / activity: Morning · Daytime · Evening
Photography difficulty: Moderate
Where to look: Scan large lakes and rivers in the cold season; in summer, mountain reservoirs and rivers with mature forest nearby.

Months confirmed by a Romanian source. General guidance, not local sightings.

Plan an outing See what to look for this month

Photography Guide

Practical starting points based on the species’ behaviour and habitat, not fixed rules.

Where and how to look: Scan large lakes and rivers in the cold season; in summer, mountain reservoirs and rivers with mature forest nearby.
Best time / activity: Morning · Daytime · Evening
Behaviour to anticipate: Diving for fish and running take-offs along the water.
Photography difficulty: Moderate
Starting shutter speed: 1/1600 sec or faster for take-offs.
Fieldcraft: Work from the bank with cover behind you; mergansers swim off quickly if approached.
Ethics: Keep well away from nests, never use playback, and leave if the bird changes behaviour because of you.

Identification

Large merganser, 58–72 cm, with a long, narrow, red serrated bill hooked at the tip. Breeding males have a dark green head, white breast and flanks and a blackish back. Females have a brown head with a crest, a white chin and a grey body, the brown neck sharply divided from the whitish breast.

Habitat

In the breeding season, deep reservoirs and rivers at higher altitudes, with forest nearby for nesting in tree holes.

Distribution

Breeds locally in all groups of the Carpathians. In the cold half of the year it can be seen on most large lakes and rivers, including along the coast.

Approximate range in Romania

Carpathian mountains and foothills · Danube valley and floodplainGeneral distribution only. This is not an occurrence map and does not show nesting or sensitive wildlife locations.

Diet

Mainly small fish, plus aquatic invertebrates, amphibians, small mammals and birds; only small amounts of plant matter.

Behaviour

Females tend to return to the same breeding areas, and to breed where they themselves hatched.

Seasonality in Romania

Breeds in Romania and is resident. In the cold season birds from the north of the range arrive as well.

PresentRareAbsentUnknown

Presence

Breeding

Migration

Wintering

About this data

Source-verified months inform the seasonal filters. Local timing can vary. Unconfirmed months do not imply absence. Presence verification is separate from monthly status; each month's details identify its verification. Lighter bands mark estimated timing. Empty event rows mean no event is recorded, not confirmed absence.

Breeding

Lays 8–12 eggs in a tree cavity, often an old Black Woodpecker hole, or among roots or dense vegetation near water. The young leave the nest within 24 hours and fly after 60–70 days. The Romanian breeding population is estimated at 20–50 pairs.

Common Merganser

At a glance

Photograph this species

Photography Guide

Identification

Habitat

Distribution

Approximate range in Romania

Diet

Behaviour

Seasonality in Romania

Breeding

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