For obvious reasons (at least if you follow baseball), it's taken a couple days to be able write this:
On Tuesday night, as our Milwaukee Brewers were being no-hit by the Detroit Tigers' Justin Verlander, the great Brewers' radio announcer Bob Uecker (a Wisconsin native) kept talking about the [si:gəls] flying around. (Sometimes, I think there was a schwa, sometimes a syllabic /l/.) Was it some weird mechanical mascot? Something for some promotion? Even with the context of things flying around in Detroit, I only figured out what this was when he used a variant of the word: gull. There was no hint of secondary stress on the second half of this compound. In fact, it was like those sailing terms where the compounds are spelled in pretty transparent ways but pronounced without a hint of their history: starboard, coxswain ([kaksən] in my limited experience, although Merriam-Webster gives two pronunciations) and gunwale (now sometimes spelled like it's said: gunnel). But I don't find this as a variant pronunciation anywhere — DARE has lexical variants for the bird name, but no entry for seagull itself, M-W doesn't give this variant, etc.
Oh god, what a bleak game it turned out to be. But the Brew Crew bounced back last night and took the Tigers, 3-2.