In Menglian County, southwest China's Yunnan Province, Baya weaver birds are doing some last-minute refining on their "houses" in preparation for the new additions to their families.

Starting in April, the males gather grasses and begin crafting their mid-air nests from scratch with their beaks. 

When the nests are halfway finished, the males will begin to lure females in with their calls. Only those whose "architecture" is considered up to standard stand a chance of mating.

Couples will leave for migration with their newborns in September and fly back next spring.

(Cover image via CFP)