Sparrows are interesting in another way: they practice undulating
>> flight. [...] > > David .. I've also seen corvids [magpies] do this as well. Corvids are passeriforms.Undulating flight would be expected to be easier for small birds (muscle power scales with the cross-section area of muscles and thus with the square of body length, body mass scales with the cube of body length), but even the largest toucans (piciforms) do it, I hear.