Use of initial capitals for specific common names varies. In some fields, common names of individual species usually have initial capitals. For example, in ornithology, both the International Ornithologists’ Union and Birdlife Australia recommend using initial capitals for the common names of bird species; however, common names that refer to a group of species are not capitalised:
White-throated Sparrow Black Honeyeater honeyeaters parrots
Common names are often capitalised in field guides, floras and faunas, and interpretive plaques at museums. For publications in a specific field, check the accepted conventions for capitalisation and hyphenation, and follow them precisely.
However, many plant and animal journals in Australia – for example, Australian Journal of Botany, Australian Journal of Zoology, Australian Mammalogy, Austral Ecology – use lower case for common names, including bird names:
white-throated sparrow black honeyeater
In general texts where no specific guidance is provided, it is preferable to set common names in lower case, unless the name includes a proper noun:
red kangaroo honey bee wattle orange-bellied parrot Norfolk Island pine Bennett’s tree kangaroo
This avoids mixtures of capitals and lower case that would otherwise occur when referring to some nonspecific and some specific names in the same publication. For example kangaroo is a nonspecific common name (because there are many species of kangaroo), whereas koala is a specific name (because there is only 1 species of koala). Use of kangaroos and koalas is less confusing for a general readership than kangaroos and Koalas.
Similarly, if a document contains, for example, common names for plants, birds, mammals and reptiles, use a consistent approach across all groups.
Reminder. Initial capitals are used only for formal names. Informal and collective (plural) references to the same item do not need capitals.
