In the summer of 1896 he decided to go on a journey of ornithological exploration to Venezuela following the advice of Wirt Robinson, who had visited Margarita Island the year before, and from his mentor Frank M. Chapman.

In San Antonio de Maturín, he met a family of British settlers, the Tuckers, and felt in love with one of the daughters, Alicia Elvira.

He returned to the United States with a small collection of specimens that he brought to Chapman at the American Museum of Natural History.

Once he finished his studies at Harvard, Phelps returned to Venezuela in 1897, to marry Alicia Elvira Tucker and settle in Maturín.

William H. Phelps and his family are commemorated in the scientific name of a species of Venezuelan lizard, Cercosaura phelpsorum.