The little bit of thought I gave to the blogs on Swallows and swifts led me to think about the broad issue of taxonomy. Taxonomy is the science of classification, a thing which can be applied to any activity but which is often interpreted as the scheme(s) of classification of organic life-forms – plants and animals. As regards the latter the ‘levels’ of the modern-day classification are; Kingdom, Phylum, Class, Order, Family, Genus and Species. As to where on the list a particular creature is placed is determined by certain common physical criteria.
As regards my recent blog the Species is Common Swift ( there are many different species of swift around the world, some not being migratory). The other different ‘levels’ in the taxonomy of the Common Swift are; Kingdom = Animalia, Phylum = Chordata (its simplest definition being animals with a backbone), Class = Aves (birds), Order = Apodiformes (long narrow wings and weak feet), Family = Apodidae (highly aerial birds) and Genus = Apus (Greek for ‘footless’).
Categories have been revised over time by a succession of distinguished biologists a fact which can lead to different reference works using somewhat different terminology. A famous person in this regard is the Swedish naturalist Carl Linnaeus (see picture) who published his taxonomies in the 1750s.