It’s a fun idea to imagine the Roman Empire discovering that birds can fly, but in reality, the Romans were already well aware of this fact. Birds flying was a common observation for people in ancient times, including Romans. They would have seen birds flying around as part of everyday life, and there’s no record of a major revelation about this phenomenon.

In fact, the Romans had a sophisticated understanding of nature and animals. They observed and documented various aspects of the natural world, including the behavior of birds. Roman writers and naturalists like Pliny the Elder discussed birds and their habits in works such as "Natural History." This comprehensive text covers a wide range of topics, including animal behavior and the natural world.

So while the Romans were certainly fascinated by many aspects of the natural world, the idea of discovering that birds can fly would be a bit like discovering that water is wet—something they would have taken for granted.