In 1924 he became a member of the Nederlandsche Ornithologische Vereeniging [nl] and published his first article in the journal Ardea in 1925.
While serving in Suriname, he found that despite work done by the Penard brothers and Charles Chubb, there were great gaps in knowledge.
So he began to make collections and sent them to museums, initially to John Todd Zimmer at the American Museum of Natural History but after Zimmer's death in 1957, he sent specimens to Rijksmuseum van Natuurlijke Historie in Leiden.
He also began to put together his notes and this resulted in the 1968 book, The Birds of Surinam with art by Paul Barruel.
[3] Haverschmidt became chief justice of the Supreme Court and served as interim governor of Suriname on three occasions.