As a miserable Lyme disease infected not quite cured tick hating person, (breath), I would pick the ticks off with my fingernails or tweezers as quickly as possible, and NOT wait for chemicals or oils or whatever to maybe smother or kill them.
The only sure way to get rid of them is to manually pull them off, as close to the skin as possible.
And check the bird over, I have found them in the cracks of the legs, on their butts, under their wings.
Deer and Lone star ticks are roughly the size of poppy seeds, and can do a world of hurt.