Grebes are pretty adorable, but this species may take the cake for cuteness. The Titicaca flightless grebe or short-winged grebe is found in Peru and Bolivia, living primarily on (you guessed it) Lake Titicaca, but also in several surrounding lakes. Though it can't fly, it can swim like a champ and catches mainly small pupfish as prey.
Unlike so many other flightless birds that have been threatened by introduced predators, the Titicaca grebe is threatened because of the use of gill nets by fishermen, which drown the birds by the thousands. It is now listed as endangered. And although some areas are protected, there is no concerted conservation effort underway for this species.