Since 1901 Census, the Census reports have recorded a significant difference in the total population of the tribe and the population that speaks Yerava tongue.

The difference between the total Yeravas and the total Yerava tongue speakers is as follows:

To explain the cause for such a difference, the 1931 Census states that "either the language figures or population figures are somewhat inaccurate". But this difference is found not only in 1931 Census, but also in some of the previous and the following Census enumerations as seen above. The table indicates that, not all the Yerava tribal population speaks Yerava. There appears to be a correlation between the increase rate of literacy among Yeravas in literate languages and decrease in the number of mother tongue returns under Yerava. This is, however, only hypothetical and the situation requires a much deeper study.

The first Census of India (1871) identifies Yeravas as people speaking a language of their own. The 1881 Census classifies the speech of Yeravas as a wild dialect. And the 1891 and 1901 Censuses identify Yerava as a 'tongue' of the tribe of that name and a dialect of Malayalam. The Linguistic Survey of India too identifies Yerava as a dialect of Malayalam. The 1921 Census identifies Yerava as one of the peculiar languages of Coorg. Similarly, the 1931 Census too identifies Yerava as one of the principal indigenous languages of Coorg. The 1971 Census indicates Yerava as a mother tongue of the tribe of that name and a dialect of Malayalam, but it advises further verification in this regard.