When Snetsinger began observing birds, there were about 8,500 known species, compared to about 10,000 in the year of her death. In 1995 she submitted a list of 8,040 species she had documented to the American Birding Association (ABA) and to the "Guinness Book of World Records". She was the first person to exceed 8,000 species observed, in 1995. By the time of her death, she had identified and documented 8,398 species, nearly 85% of the known species in the world. Her observations included 2,000 birds in monotypic genera, that is, the only species in the genus. Her detailed notes on the birds she saw were expected to lengthen her list, as some were likely to be identified as new species after her death.