The Thunder Bird, Is a Hut?

These stories could, in fact, be based on real life encounters with actual kiju like birds. There were these real, enormous and quite dangerous birds that to day are known as terratorns or terror birds. Yell, it's possible. Yet, just just smashing two instances together like that, very common in humanity, that's just whell we do. Yesi it's a hut. It's a hot thing. It's like what all the cool people are doing. This still doesn't explain everything, because the thunder bird, as depicted in mythology, is often, like, clearly avian. So how do we explain the specificity here?