Tick on Bird

Home exhausted after long day working. Found feathers all around downstairs - upset as Toots had evidently caught another bird.

Later went to draw curtains and found blackbird cowering on windowsill. It pecked me lethargically as I picked it up. Examined it to see what looked like a swollen tick on it. 
Didn't know birds got them and don't usually see them in winter. But it was a tick, so I twisted it off and took the bird outside where I put it on the bird table. It collapsed there and I feared it was dying, but later it stood up and perched on the edge. Later it was gone, so I hope it's OK.