I think in the majority of cases the name 'common' does refer to abundance or familiarity. Just that in this instance it doesn't. And I cant remember my original references for this. I researched the name 15+ years ago and found several medieval/historical texts referring to this being the gull of common land. but someone has already given Dave Okill's reference earlier, but Dave doesn't give a reference for his statement.
I think when we discuss the origins of bird names we have to consider them in a historical context, particularly for common or familiar species. Historically birds will have been known by different local communities by different names. Some of these might be very similar, some may be very different. Such historical (and I'm talking 400 years plus here) names can have their origins in appearance, sound, habitat, abundance, familiarity, affection, with reference to other species (e.g. pliver's page for Dunlin), lore and legend. For example, Wren
Troglodytes troglodytes has 164 known vernacular names (here's a selection to show just how divers these are -jenny-squit, jenny-cruddle, jenny, jenny-wren, jenny-wran, jinny-wren, Loughgilly, jinny-ran, jinny-wranl, jennywaren, jenner-hen, giller-wren, gilliver-wren, julliver-wren, kitty, kitty-wren, kitty-raan, kitty-tope, katie-wren, kitty-me-wren, brown kitty, brown kittywren, kitty-tope, nantit, nanny-fudger, peggy, sally, bob-wren, bobby-wren, robbie-cuddy, stumpy-dick, joe-cutt, joey-cutty, tommy-liden, tom-in-the-wall, tomtit, thomas-gierdet - thanks to Andy Gosler, EGI Oxford, who happen to present on this last week at the BOU annual conference and whose list of Wren names I therefore had to hand to sue here rather than having to compile it myself!).
It is only as people began to travel more that bird names began to stabilize/standardize as bird names were exchanged and some stuck and others receded in use, and it was only with the publication of the first texts that some names really began to take precedence over other names nationally. The first real text for this was
A History of Birds (1815, Anon) which listed 64 'standard' vernacular names. The poet John Clare added 75 to this initial list. Yarrell's
A History of British Birds (1871-85) picked up the thread and accepted only 33 of 64 of the list from 1815 (seemingly ignoring Clare - presumably cos he was seen as a fancy and poet rather than a serious naturalist by the established naturalists of the day), to which Alfred Newton (founder of the BOU) added another 80 species for his revision of Yarrell (again, my thanks to Andy Gosler for this summary which I have to hand).
You can see by the dates involved that the adoption of national level, rather then local/regional level, vernacular names took a long time to get going and an age for names to become adopted and it wasn't really until Victorian times onwards, when books became much more commonplace, that national level vernacular names really started to take hold and became the names which reached the field guides from the 1950 onwards and became the names we all are familiar with today.
The next step was then the globalization of bird names leading to the IOC's international standard English names which commenced in the 1980s and eventually lead to the website '
IOC World Bird Names' in 2009. These are complementary to vernacular names and do not place them at the local (national/regional) level but have helped to cement some newer vernacular names.