Ok so I have to find out why a bird being in a tree is an example of commensalism. I pretty much figured out that commensalism is when it helps one out and does not affect the other. I just can not figure out why this is an example. Someone please help, it would be greatly appreciated!:)

Commensalism is a symbiotic relationship in which one organism benefits and the other is neither harmed nor benefits. The tree is not harmed by the bird and also does not really benefit from it staying there. The Bird, however, benefits greatly in many ways including having shelter, food in buds or leaves, a safe place for the bird's young, safety from predators ets... Now do you see why?

Yes thank you so much!!