In the article Irish: A Dying Language, Laura Jean Karr states, "The main difference between all three (Scottish Gaelic, Irish and Manx) stands with Irish being the only Gaelic language that is on the Endangered Languages list. The reason that Irish has made that list is because it is considered a dying language."
This could be taken to mean that there are fewer speakers of Irish than of Scottish Gaelic or Manx. That is not, however, the case. Irish is spoken as a first language by about 80,000 people and is recognised as a working language by the EU. By comparison, there are only about 1,000 native speakers of Scottish Gaelic and Manx is no longer spoken as a first language at all (the last native speaker of Manx, Ned Kelly, having curled up his toes in 1974).
I don't know whether there's a formally and internationally recognised list of endangered languages but, if there is, I certainly imagine that Scottish Gaelic and Manx would be listed along with Irish!
That said, I'll bid you fastyr mie!