RED-BREASTED MERGANSER 
Mergus serrator, Linnaeus 
Mergus serrator, Linn., Syst. Nat., Ed. x., i. p. 129 (1758). 
Merganser crzstatus, Briss. Orn., vi. p. 237, pi. xxiii. (1760). 
Mergus albellus, Scop. Ann. I. Hist. Nat, No. 89 (1769). 
Mergus serratus, Gm., Syst. Nat., i. p. 546 (1788). 
Mergus niger, Gm., et supra (1788). 
Mergus leucomelas, Gm., et supra (1788). 
Merganser crzstatus. Leach, Syst. Cat. Mam. and B., Brit. Mus., p. 36 (1816). 
Merganser serrata, Steph., in Shaw's Gen. Zool., xii. p. 165 (1817). 
Merganser serrator {L,.), Bp. Compt., List, p. 59 (1838). 
Local Names. — Red-breasted Merganser, Saw-bill, Sawyer, Shelduck, Spear-wigeon {English) ; Sheldrake, 
Salt-water Sheldrake, Pied Sheldrake, Fishing-duck, Hairy-crown, Shelduck, Whistler, Garbill {N. 
America); Y Trochydd Brongoch (Red-breasted Plunger), Trochydd Danheddog (Toothed Diver), 
Hwyaden Ddanheddog Fronrudd (Red-breasted Toothed Duck) [Welsh); Siolta, Sioltain (Sand- 
eel Diver) {Gaelic); Topandt {Faroese); Pikkukoskelo, Tukkakoskelo, Karikoskelo, Jouhikoskelo 
Ajava {Finnish) ; Litla Topond, Hrafnsond {Icelandic) ; Vuokta-Koalsi {Lappish) ; Mindre Fiskand, 
Siland, Siden Fiskand, Stromand {Norwegian) ; Pracka, Smaskrake, Pracknisse, Stenskrake (male), 
Stenskracka (female), Skracka, Ard, Vipand, Bergand, Fiskand {Swedish) ; Ronac brokavac {Croa- 
tian) ; Morcak prostredni {Czechish) ; Toppet Skallesluger, Topskraekke, Bogeskrakke, Fiskand 
{Danish); Mittelste zaagbek, Pinduiker {Dutch); Harle huppe {French); der Mittlere Sager {Ger- 
man) ; Merganso {Portuguese) ; Mergo cristado, Serreta {Spanish) ; Smergo minore, Imperga, 
Segheta, Resegott {Italian) ; Tracro dlugodziob {Polish) ; Krahal alinnonosoy {Russian) ; Orvosbuko 
{Hungarian) . 
Egg. — Creamy-buff with a greenish-grey tinge, and sometimes of a dull stone-drab 
colour. They usually vary in number from 7 to 10, but clutches of 1 1, 12, 14 (J. A. Harvie 
Brown, V. Fauna of Sky e and N. IV. Highla^tds, p. 253), 15 (H. J. Pearson, Three Summers 
in Russian Lapland^ p. 49), and 16 (C. Collier, Ibis, 104), have been recorded. 
Average size of 109 eggs, 64.2x45.4 mm.; max., 68x46.5 and 64x47.5; min., 60.5 
X45.5 63x43.5 (F. C. R. Jourdain). Rey gives the average weight as 5.96 grammes, 
and Goebel estimates the average weight of 81 Russian specimens at 5.59 grammes. 
In Scotland full clutches are usually found in last week of May and first ten days of 
June, usually in June. 
Incubation period given by Hantzsch as four weeks. 
Down. — The down of this species is light grey with a bluish tinge, the centres being 
almost white and the tips greyish- white. See also Zoologist, 1906, p. 374 ; 1907, pp. 108-9 ; 
Brit. Birds, ii. p. 40 (feathers figured on pi. ii. fig. 18, and in the Brit. Bird Book, vol. iv.). 
Young in Down. — Crown and upper parts brown, becoming blackish-brown behind the 
wing and on the lower back and rump. Upper wing and end of the wing brown, outer 
edges white ; a large white spot joins the thighs to the white under parts, and there is a 
white spot on each side of the rump. Cheeks and sides of the neck pale red-brown ; under 
the eye, white ; from the tip of the mandible to the eye and from the lower angle of the bill, a 
blackish-brown line extends to the sides of cheeks. There is a white buff line from round 
100 
