birds breed brown Domestic Duck down drakes duck ducks eggs farm foie gras haute cuisine Indian Runner Duck mallard meat rearing abstract appearance breakable broken calcification calcium calcium-carbonate color colors colour colours cook cooking dried dry egg egg-shells eggshells empty external food fragile fragility fragmentary fragments hard-shelled hollow idiomatic-expressions idioms inside internal leftover leftovers life outer-covering outside oval ovoid Remains scattered scattering speckled surface surfaces texture textures white yolk