Red-breasted merganser

Middelste zaagbek

Red-breasted merganser (Mergus serrator)

The Red-breasted merganser (Mergus serrator) is a large sea duck from the family of water birds that includes ducks, geese, and swans (Anatidae).

Species name

Dutch name:
Middelste zaagbek
English name:
Red-breasted merganser
German name:
French name:
Harle huppé
Scientific name:
Mergus serrator

Scientific classification




Males have a head that is dark metallic green in the face with black elsewhere. Elongated feathers at the rear of the head form a long, shaggy, and double-pointed crest. Males have a white neck ring with varied body colors that include speckled brown chest, and gray sides and flanks. In late summer during molt, males resemble breeding females, except white on inner forewing is more extensive in male. Adult 

Females are largely gray brown with white on chin, throat, breast, and belly; they retain this plumage year-round. 
Males are larger than females. Both sexes have a long narrow red bill with a black tip, red-orange feet, and black wings with white patches across the inner wing. Their serrated bill is highly specialized for grasping small fish securely. 

Less whitish, more grey –brown, on breast and belly . molts towards adult during late winter. Males well have some adult Breeding plumage on flanks, Head and chest Completing adult plumage by 2nd winter.

Standard Measurements

Body Length (cm):
The male (drake) of the Red-breasted merganser measures approximately 51–62 centimeters. The female measures approximately 51–62 centimeters.
Body Weight (grams):
The male will weight about 950-1200 gram. The female will weight about 950-1200 gram.
The weight is notoriously variable and can only be used as indication!

Females first breed at the age of two years. Pairs generally form in late winter and during spring migration, although some evidence of pairing may be evident in the late fall. Breeding is late in the season, and often the young do not fledge until September. The nest is located in a sheltered spot on the ground, usually near water. It is a simple depression lined with vegetation and down. 

The female Red-breasted merganser usually lays from 7-10 brownish eggs and incubates them for 31 days.

Artificial incubating:

The ideal relative humidity for incubating most waterfowl eggs is 55% (ground nesters) and 40% (cavity nesters). The temperature is usually 37.4°C. Set ventilation as recommended by the incubator manufacturer. Eggs must be turned, either automatically or by hand, a minimum of 4 times a day. As the duckling develops there is a loss of water from the egg and the air sac gets bigger. In normal development of an egg with a 31 days incubation, the air sac occupies about a third of it three days earlier. Cleanliness is vital and ideally eggs should be moved to a separate hatcher at this point, where the humidity should be increased to 65% and even higher once they have pipped internally.

Bird banding:
Recommended closed leg band ring size for the Red-breasted merganser is 11 mm.
The leg band ring can only be applied on a young large sea duck at around 0 days old.

It doesn't matter what leg that you band, but it's good to have a consistent system.
Suggested: Left leg = Female, Right leg = Male
Maintenance food:
Lundi Exquisit
Lundi Exquisit
Lundi Exquisit
Lundi Exquisit
Lundi Exquisit
Lundi Exquisit
Lundi Exquisit

Floatable special complete food for sea birds with the highest nutritional requirements. Each chunk contains the complete nutrient spectrum. The high protein content of 35% ensures a healthy and species-appropriate diet. Spiral algae give a more magnificent coloration of plumage and sea salt promotes the salt gland.

Lundi Ibis See-Ente special
Lundi Ibis See-Ente special
Lundi Ibis See-Ente special
Lundi Ibis See-Ente special

Floating special complete food for sea birds with the highest nutritional requirements thanks to a particularly high protein content of 45%.

Ideal for daily feeding in animals that eat a lot of protein in their natural habitat. A must for "fish eaters".

Europese soort

Het is niet verboden om deze vogels te houden die van nature in Nederland voorkomen, op voorwaarde dat deze vogels in gevangenschap zijn geboren; nakweek dus. Deze vogels zijn voorzien van een gesloten pootring. Het is wel verboden om deze vogels te houden die in het wild gevangen zijn. Alleen bepaalde instanties, zoals vogelasiels en vogelhospitalen, zijn bevoegd om jonge en gewonde wilde vogels te houden. Deze bescherming van vogels wordt vormgegeven door schadelijke handelingen te verbieden zoals:het doden, verwonden, vangen, bemachtigen en met het oog daarop opsporen van vogels (art. 9 Flora- en faunawet); het opzettelijk verontrusten van vogels (art. 10 Flora- en faunawet);het beschadigen, vernielen, uithalen, wegnemen en verstoren van nesten, holen of andere voortplantings- of vaste rust- of verblijfplaatsen van vogels (art. 11 Flora- en faunawet);en het zoeken, rapen, uit het nest nemen, beschadigen of vernielen van eieren van vogels (art. 12 Flora- en faunawet).

Photos of the Red-breasted merganser

Videos of the Red-breasted merganser