I believe I read in the 800notes comments for one of the other numbers that it's the Progressive Conservative Party calling to do "voter identification". I cannot corroborate this though.
All they're doing is PIXXING me off when they can't identify themselves in the Caller Name field; I think they blank this out intentionally.
Same Conservative support getter disguised as a poll. They are also using 587-887-1871 and 587-1875. Dishonest method from a dishonest party. They seem to use a new number after the last previous one gets enough negative reports