British Diving Ducks 
his side until he responds. The male, on his part, makes a very slight " lift" in front, the 
bill being lowered and the neck drawn up. At the same time he inhales, and on releasing 
the air as he slightly sinks forward, he utters a gentle " Pu-whoo " or " Aa-u," almost a dove- 
like cry. At the moment the call is emitted, the mouth is slightly opened. The call of the 
male is repeatedly uttered, and is often made without "lifting" in front. At such times 
the head is held forward, then erected to the normal position as the cry is given. At the 
moment of calling, the whole throat is somewhat distended. When a general display is in 
progress amongst a flock of Eiders the males and females are in a constant state of move- 
ment and activity. The males often make half-turns and bows towards their inamorata, 
and utter a high soft note like the syllable "Whoop." 
The courtship of the Eider varies greatly in different localities. I have generally 
noticed it in the first warm days of March, but like many other birds which get into 
condition early in the spring, the mating instinct is at once chilled on the resumption of cold 
weather, so that in the case of Partridges the pairs of Eiders may be made up in March, 
although the flock still keeps together, but it is unusual at least in other islands to observe 
Eiders definitely paired until the ist of April. In very mild seasons, such as 1913, Eiders 
were in full display at Scampston in the middle of January, but this is somewhat abnormal. 
During the first outbreak of sexual excitement the adult male drives away any first- or 
second-year male that may happen to be with the flock of adult birds, but as a rule these 
immatures keep in flocks apart and conduct a courtship of their own, which is neither so 
full nor so serious as in the case of the older birds. In the event of the absence of adult 
males the females will, however, pursue assiduously any young male that happens to come 
near them, and will be so strenuous as to force them to pay attention to their desires. On 
May I, 1910, Mr. St. Quintin and I both witnessed the act of copulation between a 
lo-months-old male and an adult female, and though other young males of the same age were 
on the lake their courtship was only half-hearted, and they seemed to fear to go near the 
female in question. The result in this case was that the female made a nest and laid eggs 
which were unfertile, but I do not know if the pairing of the second-year male and the said 
female would be successful or not. Mr. Schioler says that the testes of second-year males 
are still somewhat incomplete. That these second-year males do actually pair with the 
female is undoubted, but that the act is only casual and not that of binding marriage 
seems to be the case, for I have not yet met any observer who has seen a pair of immature 
Eiders together in May when the female has actually made or is making her nest. Even 
if one female mated for a time with an immature, it is likely that he would sooner or later 
be driven off by an adult male who would in turn definitely pair with the female.^ 
As soon as the courtship has fully set in in April, the pairs seem to separate more and 
more from the flock, and even if they repair daily to the same feeding ground it will be 
noticed that each pair keeps apart and frequently welcome each other at almost every return 
to the surface. When the appetite is satiated the pair then fly off by themselves, and repair 
to some quiet spot near the land or island which they intend to make their summer home. 
^ Faber states {Prodromus Islandisch. Ornithologie, p. 70, 1822) that the male bird " is not capable of procreation until its fifth 
summer," whilst Professor Collett {Minor Comm. Avi-Fauna, Norway, 1881-82, pp. 284-6), in describing the advance of 
plumage of the male, says that " it may be doubtful if the male birds are capable of procreation while still in their first handsome 
plumage (2^-3 years). It is not improbable that they only attain puberty when 4 years old." These are views which are not sub- 
stantiated by fact either in a wild state or in confinement. — J. G. M. 
