A trio of Black-necked Swans hatched on August 15, 16, and 17 at Brazil's Sao Paulo Zoo.  When the adult Black-necked Swans were unable to incubate their eggs, zoo biologists moved the eggs to an incubator, where they remained for the 35-day incubation period. 

Now that the cygnets have hatched, zoo keepers weigh them daily to monitor their growth.  Every day, the cygnets enjoy sunbathing and practice their swimming skills.

Black-necked Swans are native to South America's lakes and marshes, where they feed on plant material, insect larvae, and other invertebrates.  They nest and lay eggs from June through September.  Both parents participate in building the nest, incubating the eggs, and rearing the cygnets.  Both parents will carry the cygnets on their backs.  Black-necked Swans are the largest waterfowl species in South America.

Photo Credit:  Carlos Nader / Sao Paulo Zoo