Skull pneumaticity - Skull pneumaticity in wildfowl in relation to their mode of life

Abstract

The bones of birds contain air--an adaptation which results in a relative lightness for flight. This is a generally accepted fact, but one which may well require modifying as our knowledge of the air systems of birds grows. The large, highly pneumatic skull of an owl is one of the best examples of this adaptation, but by no means all birds have such skulls, and this is particularly true of wildfowl. I have so far studied the skulls of 68 different species of wildfowl, and although I still have some gaps to fill, the findings do indicate a high degree of functional adaptation, although much remains to be discovered. I have yet to find a single skull which is fully pneumatised. There is a basic pattern of pneumatisation which appears to be common to most geese, the swans and dabbling duck.