Several expeditions to collect and document bird species in Venezuela took place in the 1930s and 1940s. These included one to Amazonas state by Ernest G. Holt for the Smithsonian, collecting over 3,000 specimens; a party led by William H. Phelps and his son, including Ernest Thomas Gilliard and Fèlix Cardona i Puig, which recorded over 2,000 specimens on Auyán-tepui; and a small collection amassed by F. D. Smith in Anzoátegui and Monagas. The Phelps family contributed significantly to the study of Venezuelan ornithology; an American explorer, William H. Phelps Sr. traveled extensively to the country, where his son was born and raised and where the William Phelps Ornithological Collection is kept. This collection grew from a series of expeditions to Venezuela's islands, tepuis, rural flatlands, great plains, and deserts.