Hi,

when 'western lowland' are adjectives name (indirectly) describing a species of gorilla, write it with common letters, when it is the official name of the animal it should be capitalized. The same goes for the black tip reef shark.

Personal names are capitalized, common names not.
Gorilla is a name common to all animal of this type (therfore written with common letters)

Since western lowland is common to all gorillas from this region (common letters)


Further, western is not being used in this sense to indicate direction, but explain from which region the gorillas come.

to make things a little easier:

if you are using the capitals to indicate that the object being named is known as XYZ, i.e. it is its name, then the capitals are correct.

if you are using the words to qualify the type of object, as in Lowland Gorilla, then capitals are incorrect.

so, in your case, Western Lowland Gorilla is the name of a typical gorilla type.

in running text, where capitals have been used to introduce the phrase, you may continue to write without capitals.
see here:
http://www.thebigzoo.com/Animals/Western_Lowl...

Sorry, I messed up the rules:
1. uppercase for regions
2. lowercase for directions

Then it would be Western Lowland gorilla, as this gorilla species comes from the Western Lowlands of Africa, right?

@odondon irl:

Ok, then it's Western lowland gorilla. But why is "lowland" not capitalized? I thought it was part of the region's name, as there also exists an Eastern Lowland Gorilla - I am introducing this species to you, that's why I'm using capitals, right?

It is (at least for the US):

Down South
Up North
Out West
Back East

We already discussed shortly whether all species names should be capitalised or not: related discussion - without conclusion if I remember rightly.