3. PREPARING SKINS 



27 



Fig. 19. Pneumatization of the skull. An enlargement of the cut skull shows the 

 appearance of the pneumatized layer. The same skull shown from above (reduced in 

 size) indicates how un-pneumatized areas appear. Diagrams 1-5 show reduction of 

 pneumatization with age. 



line diagram of the cranium indicating the shape and extent of any trans- 

 parent windows should be added to the label and/or data records (fig. 19). 

 Particularly in small birds, where the skull is in any case very thin, it may 

 be difficult to be certain if and where such windows occur. The examination 

 of any cut edges and the inside of the skull with a hand lens may help in 

 determining if any are present. The presence of sutures, lines indicating 

 the separate bones of the cranium, should also be noted. These are present 

 in very young birds and disappear in adults. 



Sexing 



If the skinning has been done carefully the carcase that has been removed 

 should consist of the entire undamaged trunk with some limb bones attached. 

 This carcase, particularly in the case of rare species, could provide valuable 

 information on structure, musculature and internal anatomy. Ideally the 

 most satisfactory method is to treat this as though it were a whole specimen 

 and prepare it in a similar manner (p. 33), taking great care to see that it is 

 marked with the same reference number as the skin and that it will be possible 

 to relate skin to carcase. Sex, gut contents, and similar information can 

 then be obtained from the carcase at a later date. If, however, this is not 

 possible and the carcase cannot be fully preserved the following examination 

 should be carried out. 



Before the carcase is discarded it should be opened up to determine the sex 

 of the specimen by examining the sexual organs. Do not sex the specimens 

 from the plumage and if it is not possible to examine the sexual organs, 

 merely note this and leave the specimen unsexed. 



