In his early years, Fraser was curator of the Museum of the Zoological Society of London.
He participated in the Niger expedition of 1841 as the African Civilization Society's scientist, with Allen and Thomson.
He wrote Zoologica Typica, or figures of the new and rare animals and birds in the collection of the Zoological Society of London, a lavishly illustrated large-sized book, published in 1849.
[4] Around 1857–1859, he collected birds and mammals in Ecuador for Philip Lutley Sclater of the Zoological Society of London, and the year after in California.
[4] Fraser wrote a Catalogue of the Knowsley Collections (1850) and described several new species including the Derbyan parakeet Psittacula derbiana named after his employer.