The Books of Order. Primo.

I would like to organize a compendium on birds, but I have no idea on how to do it. Alphabetically is not an option.
What are the perfect criteria?
Origins. Sizes (of the beak? the wingspan? height?). Number of colours or colour-pattern? Types of colour (hot, cold, bright, in relation to colour spectrum physical measurements?) Symbolically? But then again, is the cock the National Symbol of France, the Redemptive one of Portugal, or the Guardian of Korea? Nourishment (parakeet eats insects, owls and eagles raw meat, parrots fruit, vultures and secretaries rotten meat). Popularity. Rareness (the Dodo) or Abundance (pigeons)? The way they stroke their beaks together in, as it were, a kiss, or the way they feed their chicks. Maybe the seduction rituals or the mating dance. Separating the ones that migrate and the sedentary ones. The real, the existent, the imaginary birds, such as the Phoenix, the Simurgh, Arjuna’s bird, the Barcelos’ cockerel. The beak curvature: from the eagle to the parakeet. Strength? From the docile to the aquiline. Intelligence: from the chicken to the falcon. A separate leaflet for birds who occupy other bird’s nests and throw away their eggs, as the cuckoo. Birds who have no problem in caressing offspring not their own.