What is the submoustachial?

The feathers along the side of the lower jaw have a very confusing history of terminology. They've been called the malar stripe (in many early and mid 20th century bird books), the submoustachial1 stripe (in most bird guides published in the 1980s and later), and the malar again (in my Sibley Guide to Birds).

Savannah Sparrow with some head feathers and head feather markings labeled. Note that the moustachial stripe is part of the auriculars, not a distinct feather group. Original gouache painting and pencil outline copyright David Sibley.

The trouble really started in 1981 when – in an effort to standardize feather descriptions – "submoustachial stripe" was introduced and the term "malar stripe" was shifted down to describe a dark stripe on the side of the throat. That was wrong, so in 2000 I proposed the new term "lateral throat stripe", and reverted to the old use of malar (replacing the new "submoustachial").

All of that proved too confusing, and while "lateral throat stripe" has been adopted by many, the term malar has continued to have two meanings2, neither of which fits its dictionary definition of "related to the cheeks".

In a recent commentary in British Birds, Keith Vinicombe and Lars Svensson point to all of this confusion and suggest simply retiring the term "malar", and I agree completely. They go on to endorse the term "lateral throat stripe" and further suggest that, for the feathers on the side of the lower jaw, the best term is the already established "submoustachial".

After long consideration, I agree. My only hesitation comes from my personal bias against the word submoustachial. It seems unnecessarily complex and dependent, like describing our jaw-line as "below the moustache". It's a significant and always-recognizable feature. Why is it named with a reference to something less constant? I would like to see a new term like "jaw stripe" used for these feathers along the side of the lower jaw, but I understand that there really isn't a pressing need to fix this, and I will accept submoustachial.

Because this was a British proposal, the spelling is British "moustache" rather than the American "mustache", and American bird guides have continued to use that spellinge.g. the newest edition of the National Geographic field guide still calls the dark stripe on the side of the throat the "malar stripe"