Retrievers, Standard Poodles and Irish Water Spaniels may compete in retriever field trials, while retrievers,  Irish Water Spaniels, Barbets and Standard Poodles may enter hunt and working certificate tests. Dogs are tested both on their ability to mark the location of downed birds and on their retrieving skill, over land or in the water. At the higher levels, dogs are required to carry out very sophisticated retrieving tests, including marking multiple birds and finding unmarked birds (blind retrieves).  
(Description courtesy of Canadian Kennel Club)