Urbanised by William Marsland.

[Touchstone]

A countryside of sorts
arrives in a flurry on the fifteenth floor
finches, mating pairs.

I really like that (and the title as well).

Flitting from balcony to concrete balcony
darting, diving, weaving
through paint peeled drab, playing
catch-up on the wing.

I think you've tried to fit too much in there. I'd lose either "weaving...drab" or "playing...wing." Probably the latter (see below for the reason why).

when they alight outside the window
their light dissolves the tragedy of towers.

Sorry but I don't like that much. What light? They're finches not phoenixes. And "alight" and "light" are too similar to sit well so closely together.

I think "tragedy" is too strong a metaphor. You've got some countryside creeping back, and concrete is dull, but tragedy would fit more naturally into something about a forest being bulldozed. Perhaps "mocks the hubris of towers" or something like that would be more in keeping.