As a starting point: any musical performance that is recorded in any form already has an automatic copyright in the recording of that performance. In other words, nobody could sample or otherwise exploit your recorded performance without your consent.
So the real question we need to ask: are drumbeats considered songwriting? If they are, then they form part of the musical composition and would be protected under the law just like a chord progression, melody or lyric.
The short answer: unfortunately, no. Drumbeats and drum patterns are not typically considered songwriting. The law makes clear that lyrics, melody, harmony and rhythm can be copyrighted. Most often, lyrics and melody are afforded protection under the law before the other two. This is arguably because the latter two are considered “accompaniment,” while the first two form the backbone of the composition, and remain consistent regardless of who is performing the composition.