Bird that barks instead of sings
The Antpitta avis canis Ridgley is a bird that looks like a stuffed duck on stilts and barks like a dog. The bird was discovered by ornithologist Robert S. Ridgley in the Andes in Ecuador in June 1998. Thirty of these long-legged, black-and-white barking birds were found. It apparently had gone undetected because it lives in remote parts and, of course, doesn’t sing. The size of a duck, it is one of the largest birds discovered in the 20th Century.
On the other hand, there are dogs that do not bark! The basenji, a smallish dog with a silky copper coat, does not bark. Instead, it yodels when it get excited. Wild dogs like the African Wild Dog also do not bark.
Basenji – Avuvi voiceless dog
More info at Wikipedia