INTRODUCTORY 35 



It will be found a good plan to secure those loosely 

 made nests with a needle and thread, making stitches 

 here and there which will strengthen the nest, and 

 yet remain practically invisible. As soon as a nest is 

 taken a label should be attached. This need not 

 contain anything beyond a reference number to the 

 note-book, in which all particulars must be fully 

 entered at the time. Leave nothing to memory. In 

 the case of a nest that is under observation whilst 

 building, minute details can be recorded as the work 

 progresses ; and let the student bear in mind that it 

 is this detailed observation that is specially required, 

 even relating to common and familiar species. Con- 

 cerning the nest-building habits of vast numbers of 

 exotic birds we know literally nothing, and in this 

 direction lies som.e of the most fascinating w^ork open 

 to the caliologist. The facts to be observed are 

 almost endless : the peculiarities of the site, any 

 special display of intelligence on the part of the 

 architects, such as in its concealment or in the 

 materials selected, the building sex, the time of 

 building, the duration of the work, and the methods 

 of putting the materials together so far as can be 

 observed, may be given as a few of the more salient 

 ones. Nests should be taken for the collection as 

 soon as the eggs are deposited, for they are then at 

 their best. As nests are as much liable to the attacks 

 of insects as skins or furs it becomes absolutely 

 necessary to apply a preservative of some kind. 



