Where nest sites were not accessible, size and plumage development were gauged by telescope.
On it shone the plumage of the bluebird of illusions.
For species with significant amounts of white in the plumage, this makes seeing the bird very difficult.
All the ivory gulls observed were in adult plumage (all white, no black speckling).
Seeing himself admired and applauded, master raven shed his plumage and changed his song.
Age was determined by plumage analysis for 159 adults (birds older than 1 year) and 76 young (4-7 months old).
Their plumage is in fact dissimilar, though they are embroidered in different combinations of the same colours;39 but it is not their physical characteristics that are important.
Hence, not just black ravens are to be considered naturally possible but also white ravens and ravens with no plumage at all.
