Collective nouns are almost always singular in form, which means they require a singular verb. Yeah, it's bizarre… but so is the entirety of the English language.
"On Survivor, the tribe vote out a member every three days."
"On Survivor, the tribe votes out a member every three days."
The first sentence is incorrect because the collective noun tribe is singular, but the verb vote is plural. They don't match. The second sentence is correct because it matches a singular collective noun (tribe) with a singular verb (does). Plus, "the tribe have spoken" just doesn't have the same ring to it.