THE THRUSH GENUS 371 



The mistle-thrush is by no means always as happy in his encounters 

 with his enemies. His habit of building his nest early in the year, 

 before the leaf is out to give it cover, and of placing it in a conspicu- 

 ous position, generally in the fork of a big tree, renders it easily visible 

 to the keen eyes of crows, magpies and jays. As these birds have an 

 appetite for eggs unrestrained by any prejudice in favour of freshness, 

 they are ready to gratify it whenever occasion offers and whatever the 

 stage of incubation. Mistle-thrushes therefore, in spite of their valour, 

 lose a number of first clutches, a loss which helps partly to account 

 for the scarcity of the species as compared with blackbirds and 

 thrushes whose nests are not raided to the same extent owing to the 

 fact that they are placed as a rule in less conspicuous sites. 1 



In the construction of the nest the cock mistle-thrush is said to 

 assist the hen, but to what extent and whether the habit is general 

 are questions that cannot be answered, so scanty is the evidence 

 available. What is known of the cock blackbird's attitude towards 

 nest-building shows that with respect to this habit at least a certain 

 variation in the behaviour of the individuals of a species may probably 

 be regarded as normal. This conclusion, if it can be shown to be 

 exact, is important, for it will explain the contradictory evidence often 

 supplied. 2 It will also help to correct any tendency to assume that 

 the male normally aids the hen in nidification because one or two 

 individual males have been seen to do so. Further observation may 

 show that non-participation by the cock, though less frequent than 

 the converse, is nevertheless more a normal than an accidental mode 

 of behaviour. The cock blackbird's behaviour ranges from active 

 participation to complete indifference. Two cases are recorded in 



Corsica, where there are thousands of acres of timber and very few breeding birds, he has seen 

 the mistle-thrush and chaffinch nesting together though there was probably not another nest 

 of either species within a mile. This certainly weakens the view that the proximity is due to 

 mere chance. But the explanation of Vian assumes a foresight on the part of the chaffinch 

 which is difficult to credit. 



1 Dr. N. P. Ticehurst, in his Birds of Kent, states that in this county mistle-thrush's nests 

 are robbed of eggs and young by jays to such an extent that not one out of six of the first 

 clutches are hatched or the first broods reared. 



2 See, for instance, as a good example of this, the " Classified Notes" on the bullfinch under 

 Nest and Eggs, p. 82 above. 



