 At Melbourne University he met fellow science student, Mary Sigrid Collie, and they married in 1931, the year in which David Fleay graduated in Zoology, Botany and Education.Between 1931 and 1934, Fleay taught at the Ballarat Church of England Grammar School and at State primary and secondary schools, while continuing his private study of native animals.By 1934 his reputation as a "wildlife man" was sufficiently established that, when Melbourne Zoo decided to set up an Australian section as part of Melbourne's centenary celebrations, David Fleay was chosen to design and direct the section.