EUROPEAN BLACKBIRD 77 



eight, and even nine are recorded (Jourdain). Five or six is con- 

 sidered typical in Germany (Niethammer) . 



Young. — Incubation is performed by the female only. A good 

 many observers have flushed male blackbirds off eggs, and this has 

 led to the assertion that the male occasionally takes part in incuba- 

 tion. But Lt. Col. B. H. Ryves (1943) has pointed out that such an 

 assertion in this and analogous cases is probably not justified. There 

 is reason to believe that in such instances the male is doing no more 

 than "brood" the eggs and is incapable of incubating them in the 

 proper sense of bringing sufficient warmth to bear on them for de- 

 velopment to proceed. Colonel Ryves found that eggs which had 

 been brooded for 35 minutes by a male blackbird, whose mate was for 

 some reason losing interest in them, were still almost cold when he 

 left them. 



According to Jourdain incubation usually begins on completion of 

 the clutch. The incubation period ranges from 12 to 15 days, but is 

 usually 13 to 14. C. and D. Nethersole-Thompson (1942), in a de- 

 tailed survey of eggshell disposal by British birds, mention a female 

 having been seen with a shell in her bill, and shells may often be found 

 in the vicinity of nests. The young are assiduously fed by both 

 parents and usually leave the nest in 13 to 14 days, though 12 and 15 

 days have also been recorded. Observers contributing to a recent 

 investigation on nest-sanitation (Blair and Tucker, 1941) found that 

 the feces of the nestlings are generally swallowed by the parents for 

 about the first week after hatching and sometimes longer, while in 

 the later stages they are usually carried away. The droppings are 

 deposited by the young on the rim of the nest from about the eighth 

 day. "Injury-feigning" by birds with young has been recorded, but 

 is rare: It has also been recorded at least twice by a bird off eggs. 



Plumages. — The plumages of the blackbird are fully described by 

 H. F. Witherby (1938, vol. 2) in the "Handbook of British Birds." 

 The nestling has fairly long, but rather scanty down of a pale buffish- 

 gray color, distributed on the inner supraorbital, occipital, humeral, 

 ulnar, and spinal tracts. The flanges of the bill are pale yellowish 

 white externally, and the mouth inside is deep yellow without spots. 



The juvenal plumage is not unlike that of the adult female, being 

 umber-brown above, but not so dark as most females and more in- 

 clined to rufous, with rufous shaft streaks on the feathers, rather 

 noticeable on the wing coverts. The underparts present a more 

 definitely mottled or spotted effect than in the female, having a paler, 

 rufous-buff ground color with dark brown markings. The young 

 females tend to be less dark than the males, but there is much indi- 

 vidual variation in both sexes. In their first winter and summer 



