Flightless Birds That Make Up a Rookery

This page is the CodyCross answer for the clue below from Past and Present Tech, Group 1447, Puzzle 3 (Cathode Ray Tube).

Question is: Flightless Birds That Make Up a Rookery

and the answer is: PENGUINS

Word Meaning:

PENGUINS — plural of penguin

Definitions from Wiktionary.