Salesian missionaries worked to protect and preserve Selk'nam culture. Father José María Beauvoir explored the region and studied the native Patagonian cultures and languages between 1881 and 1924. He compiled a vocabulary of Selk'nam of 4,000 words and 1400 phrases and sentences, which was published in 1915. He included a comparative list of 150 Ona-Tehuelche words, as he believed that there were connections to the Tehuelche people and language to the north. German anthropologist Robert Lehmann-Nitsche published the first scholarly studies of the Selk’nam, although he was later criticized for having studied members of the Selk’nam people who had been abducted and were exhibited in circuses.