If there were other intelligent species, they left no traces of civilization.
And I don't think it's hubris. Our brains have gone on a specific path with many incremental steps along the way. I don't find it surprising that other animals haven't gone down the same path. That would be some remarkable convergent evolution.
Why? Flight took many incremental steps to become viable yet it has evolved at least four times independently. I think it would be harder to have flight evolved separately four times than intelligence. Not every mammal, fish, reptile, bird, or insect has limbs capable of becoming wings without major changes, yet they all have brains.
They all have brains, but very different ones. It depends on what you mean by "intelligence," also. Other animals have brains that are very good at doing what they need to do. Any pigeon is able to judge the areas of shapes better than any human. It's something they seem able to do in a flash, judging from the speed they peck the correct answer to get their food. It's also something they need to be able to navigate through tree branches and, in the modern world, buildings. We have to think about it.
They also spend a lot of brain power adjusting their eyes to cancel out the shakiness caused by their wings beating. We can't do that.
I don't think our brains would be very useful to a pigeon. We ended up on a different path, and our brains have dedicated areas for doing things that are important to us, like processing meaning from speech and recognizing faces. We really need speech because we don't have many instinctual responses to rely on and have to learn everything from our parents. We're aided in this by an excellent ability to form concepts.
This seems far more specialized to me than a specific mode of transportation. I should point out that our monkey-like ancestors were quite unusual in that area. Swinging from branch to branch is not a commonly adopted method of transportation.
Which brings up another point, which is if there were other "intelligent" animals they probably don't have any modern descendants. We still have the arms and neck of a tree-swinger. We still share brain structures with reptiles. It would be very odd for these specialized brains to develop and not have a trace of them today in birds.
But of course, there's no point actually bringing real science into this discussion.