City in ancient Crete with renowned labyrinth / TUE 11-29-22 / Hit BBC series since 1963 informally / Ratite featured on Uruguayan currency / Goose that might nest on volcanic ash

Constructor: David Rockow

Relative difficulty: Easy (very)

THEME: FEATHER (37A: Element of plumage ... and a feature shared by every answer crossing this one) — seven BIRDS (1D: Tweeters) form a makeshift FLOCK (51D: Gathering of 1-Down, like that found in the center of this puzzle) at the middle of the grid:

The FLOCK:

• FALCON (37D: Its peregrine variety is the world's fastest avian)
• WREN (28D: Small brown passerine that holds its tail upright)
• RHEA (24D: Ratite featured on Uruguayan currency)
• KESTREL (25D: American raptor that's the size of a mourning dove)
• HAWK (38D: Iconic metaphor for keen-eyed watchfulness)
• NENE (35D: Goose that might nest on volcanic ash)
• CONDOR (19D: Its Andean variety has the largest wingspan among all raptors)

Word of the Day: KNOSSOS (22A: City in ancient Crete with renowned labyrinth) —

Knossos (also Cnossos, both pronounced /(kə)ˈnɒsɒs, -səs/; Ancient Greek: Κνωσός, romanized: Knōsós, pronounced [knɔː.sós]; Linear B: 𐀒𐀜𐀰Ko-no-so) is the largest Bronze Age archaeological site on Crete and has been called Europe's oldest city.

Settled as early as the Neolithic period, the name Knossos survives from ancient Greek references to the major city of Crete. The palace of Knossos eventually became the ceremonial and political centre of the Minoan civilization and culture. The palace was abandoned at some unknown time at the end of the Late Bronze Age, c. 1380–1100 BC; the reason is unknown, but one of the many disasters that befell the palace is generally put forward.

In the First Palace Period (around 2000 BC), the urban area reached a size of as many as 18,000 people. (wikipedia)

Well this is weird, so it's got that going for it. I do love birds—love them—and so I am always going to be generally warmly inclined to a bird-themed puzzle. This one is mainly just ... a bunch of bird names smushed together. And a couple of those bird names (RHEA, NENE) are straight-up crosswordese, such that you'd never really recognize them as thematic elements. I want to say they don't count ... but of course they do. It's just that you're not apt to see them as special, given that you see them all the time. It's weird ... nothing in this theme feels particularly thematic *except* the smushing. I mean, what've you got, fill-wise? BIRDS? FLOCK? FEATHER? And then the birds, of course, but only one of those gets up to even seven letters long (which is also my favorite bird in the grid—KESTREL! Pretty sure we saw one just last week in central Colorado, sitting on top of a leafless tree ... watching ... Raptors!). My point is that none of the thematic stuff really feels thematic except through the process of smushing, which this puzzle is calling a FLOCK, but LOL the KESTREL scoffs at the idea of flying in FLOCKs with these other birds. Hell, the KESTREL would eat a damn WREN (probably). But then I guess you couldn't very well have your FLOCK be WREN WREN WREN WREN WREN WREN WREN now could you? It's a funny idea, this rag-tag FLOCK. I don't like that FLOCK (the last Across answer) comes after BIRDS (the first). Feels backwards. Also, really don't like that BIRDS is clued as [Tweeters]. None of the birds in that FLOCK is a "Tweeter." Again, the KESTREL scoffs, as she will. Don't like SEED thrown in as "bonus" answer (better and more elegant to keep the non-theme parts of your grid bird-free), just as I don't like trying to pass off PEACE CORPS and URBAN AREAS as bird-related (a strettttttttttch). Oh, and your longest answers (grid-spanners!) have *nothing* to do with the theme? Weird. But I do love those answers, so maybe I'll just think of this as an easy themeless with a dense bird center, and for a Tuesday, that's enough.