105 



mage, shows even strong moult of head and neck). An investi- 

 gation of this kind can't make out whether those late monitors 

 only occur among the youngest of the so called old birds (for in- 

 tance among the three years old birds) or whether they are northern 

 breedingbirds. Both might be the case. It still must be remarked 

 — perhaps as a general rule for birds of all years — that the 

 downmoult lasts longer than the moult of the contourfeathers, often 

 beginning before the latter and always finishing after it. 



It follows from what we saw above that the moulting-period in 

 these birds (from 30 months old and older) lasts from the middle 

 of November till the end of February. 



Bird from one to two years old. — The moult of these 

 birds, then about 18 months old, does not seem to begin before the 

 first half of January. Though less often than in the old birds, it 

 does not seldom occur that the autumn-moult has not yet finished 

 (downfeathers growing on the chin and contourfeathers on the unter- 

 side) when the springmoult begins. A rather great part of the birds 

 is much later and even a female of March 9th (1921) still seems to 

 be in complete winterplumage (the inside of the skin of head and 

 neck however showing strong moult). The majority however has 

 made more or less progress towards the beginning of March; April- 

 birds in uncomplete breedingdress are, rare though a number of 

 them still shows growing feathers on examination of the inside of 

 the skin, even towards the end of the month (2 cf cT, April 24th 

 and 25th, 1922). 



As already stated (see footnote) no few of the one year and two 

 years old birds show a more or less strong moult of the body- 

 feathers, especially of those of the underside, whereas the old birds 

 rarely moult more than the flanks and some few feathers of the 

 underside. 



We saw that the moulting-period in these birds (from 18 to 24 

 months old) lasts from the beginning of January to the 

 end of April. 



Bird in its first spring. — Birds which have safely passed 

 their first winter and are going to be one year old in the following 

 summer, moult later. The first of them with growing new feathers 

 I found at the end of February and the beginning of March. In 

 the second half of March the first of these feathers may become 

 visible from the outside (March 15th, 1921, cT with throat- feathers 

 not quite of the length of the old feathers; March 28th, 1921, bird 



