Bird field guide · Ducks, Geese, and Swans

Photographing the Red-breasted Merganser

How to photograph the Red-breasted Merganser (Mergus serrator): the right lens for its size, shutter speeds for perched and moving animals, and when it's most often seen (January, February, March and April).

30–160 cm1/2000–1/3200 s
30–160 cm
Typical length (family range)
1/640 s
Shutter: perched / still
1/2000–1/3200 s
Shutter: action / flight
f/6.3–f/8
Aperture
43,543
Research-grade sightings in N. America
ModeManual + Auto ISOLock shutter & aperture, let ISO float
Shutter (still)1/640 s
Shutter (action)1/2000–1/3200 s
Aperturef/6.3–f/8
FocusAF-C + subject/eye detectionGet low to the water for an eye-level perspective; expose for bright plumage to avoid clipped whites.
DriveHigh-speed burst
Lens100–400 mmFull-frame equivalent

Focal length needed to frame it#

For a subject about 95 cm long filling a third or half of the frame width horizontally.

Distance⅓ of frame (FF)½ of frame (FF)⅓ of frame (APS-C)⅓ of frame (MFT)
5 m (16 ft)62 mm93 mm41 mm31 mm
10 m (33 ft)124 mm186 mm82 mm62 mm
15 m (49 ft)185 mm279 mm124 mm93 mm
20 m (66 ft)247 mm372 mm165 mm124 mm
30 m (98 ft)371 mm558 mm247 mm185 mm
50 m (164 ft)618 mm930 mm412 mm309 mm

When to find it#

Jan: 15% Jan Feb: 15% Feb Mar: 19% Mar Apr: 18% Apr May: 6% May Jun: 2% Jun Jul: 1% Jul Aug: 1% Aug Sep: 1% Sep Oct: 2% Oct Nov: 8% Nov Dec: 12% Dec
Share of iNaturalist observations by month across North America. Peak months: January, February, March and April.

About the Red-breasted Merganser#

The red-breasted merganser (Mergus serrator) is a diving duck, one of the sawbills. The genus name is a Latin word used by Pliny and other Roman authors to refer to an unspecified waterbird, and serrator is a sawyer from Latin serra, "saw".

Summary adapted from Wikipedia via iNaturalist (CC BY-SA 4.0).

Field-craft tips#

  • Winter is peak season for colourful drakes.
  • Morning side-light reveals iridescent head colours.
  • Get low to the water for an eye-level perspective; expose for bright plumage to avoid clipped whites.
  • Sightings peak in January, February, March and April, which is when you'll have the most chances.

Ethics#

  • The welfare of the animal comes first: if it changes its behaviour because of you, you are too close.
  • Stay on trails, respect closures around nests, leks, dens and haul-outs.
  • Avoid playback and baiting in sensitive seasons; never bait predators.
  • Don't share precise locations of rare, nesting or roosting animals publicly.

More Ducks, Geese, and Swans#

Mallard MallardAnas platyrhynchos Canada Goose Canada GooseBranta canadensis Wood DuckAix sponsa Bufflehead BuffleheadBucephala albeola Northern ShovelerSpatula clypeata Common Merganser Common MerganserMergus merganser American Wigeon American WigeonMareca americana Hooded Merganser Hooded MerganserLophodytes cucullatus

Frequently asked questions#

What lens do I need to photograph a Red-breasted Merganser?

At about 95 cm long, a red-breasted merganser fills a third of a full-frame image at 10 m with roughly 124 mm, or at 20 m with 247 mm.

What shutter speed should I use for a Red-breasted Merganser?

1/640 s when it's still; 1/2000–1/3200 s for action.

When is the best time to photograph a Red-breasted Merganser?

Observations in North America peak in January, February, March and April. Early morning and late afternoon give the best light and activity.

Sources & licences#

Last updated October 03, 2026 · How we calculate · Sources