The strength of guinea fowl (Numida meleagris) egg shells

Abstract
The strength of guinea fowl egg shells has been studied by piercing and snapping methods and the results were compared with those from the domestic hen. Guinea fowl egg shells are stronger and thicker than egg shells from the domestic hen and the shells are stronger even after allowing for their greater thickness. The difference in snapping strength between shells of the two species is far greater when the shells are snapped inwards than when they are snapped outwards. Studies of the crystal structure, histological structure and chemical analysis revealed interesting differences between the two types of shell but it was not possible to say which of these differences accounted for the differences in strength.