The swiftlets of Asia are in trouble because these structures are snatched to make soup
The group contains around thirty species mostly confined to 
southern Asia, ... Swiftlets have four toes, except the Papuan swiftlet which lacks 
the hallux... [DOC] [TLE] Glossary - Cornell Lab of Ornithology - Cornell University [PAR] of birds that may have connections into the bones of the pelvis ... many swifts, 
including the Edible-nest Swiftlets of Southeast.