This controversial information comes from a PEGforum thread, “naming conventions for flora and fauna – cape nature“, that started on Tuesday 7 May 2024 at 12:56:22. (Note that Cape Nature is legally CapeNature.)

The first PEG member quoted from that month’s CapeNature newsletter: 

Birds: Capitalise the first letter of each word in the name, like “African Penguin” or “Cape Cormorant.” This distinguishes a taxonomic species from a general description of a bird.

Animals: Capitalise only the proper noun in the name, such as “Cape mountain zebra.”

Plants: Write the scientific name in italics, with names down to the genus level starting with a capital letter and the species in lowercase. For example, the king protea is “Protea cynaroides.

Another PEG member disagreed with CapeNature, saying:

“I … have my doubts about CapeNature‘s approach and will definitely not be following their advice. I will stick to the traditional binomial name system and common usage (

“I will be writing African penguin, Cape penguin or South African penguin (, and certainly not Penguin with a capital. I will rather trust my Sasol bird guide (”

A third PEG member said:

As an ornithologist, I know that some publications follow the rule about avian common names that Cape Nature gives here, but it is certainly not universal.

I also want to point out that the rules they give for the scientific names of plants (Latinate species and genus names) apply to all species, not just to plants.

Something that one needs to look out for when editing texts that mention species by name is consistency in how common names and scientific names are presented. In some publications, the rule is to give one name followed by the other in brackets, while other publications dispense with the brackets. The decision of whether to use common or scientific names predominantly throughout the text usually depends on the type of species and study the text deals with, but of course it is best to be as consistent as possible throughout each text. It is not unheard of for botanical studies to use mainly the common names of the plant species involved and give the scientific name only at the first mention of each species, although this CapeNature guidance seems to imply that one would only ever use scientific names for plants.

As with so many other things, there are few blanket rules, and the publication or university’s style guide should be consulted, if possible — and if no guide is available, then consistency is king!