During the last few years of his life, he worked on categorizing and annotating the large quantity of photos and audio recordings (141 songs) he had made while living with the Nunamiut in 1950. The effort resulted in a booklet, "Songs of the Nunamiut", with an accompanying CD containing the audio material. This is an extremely valuable contribution to the preservation of the Nunamiut culture, because it turned out that much of what he had gathered in the mid-20th century was now lost locally and was only preserved in his recordings. According to archaeologist Lewis Binford, the Nunamiut depend on meat more so than any other living hunter-gatherer group. The annual cycle of Nunamiut life revolves around the annual migrations of caribou. Spring: The main caribou migrations happen in March and April, when caribou move north through Anaktuvuk Pass to feed on the plains. Summer: The plains thaw and become a marshland swarming with blackflies and mosquitoes. Autumn: The caribou hunting cycle repeats in September and October when caribou retreat south again. Winter: There are about 72 days of total winter darkness starting around November 15. The native language of the Nunamiut is a dialect of Iñupiaq. In the late 1960s, the University of California, Berkeley sent undergraduate linguistics student (now Arctic explorer) Dennis Schmitt to the Nunamiut to study their dialect. There are few native speakers today. The Nunamiut speak English. Their culture is contrasted by strong collectivist and individualist tendencies, both of which are reflected in their "uncertainty language game". This involves one of five statements as part of a response: "I don't know", "maybe", "probably", "I guess", and "might be". Choosing the neutral "maybe" over "yes" or "no" reflects the cultural importance of a collectivist community. It also reflects behavior avoidance of an individual making a false statement.