__ Clocks Mark Each Hour With a Bird Call
Puzzle 1 of Time Hard Pack
Question is: __ Clocks Mark Each Hour With a Bird Call
and the answer is: CUCKOO
Word Meaning:
CUCKOO — Any of various birds, of the family Cuculidae within the order Cuculiformes, famous for laying its eggs in the nests of other species; but especially a common cuckoo (Cuculus canorus), that has a characteristic two-note call.
Definitions from Wiktionary.