Compared to the cinerous vulture, that bird he had just seen was not much different from modern birds in terms of flight speed, size, posture, and call. Most importantly, it was much smaller than the cinerous vulture.
That is the kind of transformation Yan Fei lacks; the ability to emulate modern birds and fly freely in the city without attracting attention.
Even though insects have evolved unnoticeably, their flight speed is incomparable to that of birds. Moreover, their peculiar appearances might bring trouble if they were ever caught by an attentive person.
Each time he went to the Provincial City during the day, he had to transform into an insect on the outskirts to fly over, creating not only inconvenience but also the risk of being discovered.
If there were a transformation into a small bird, all these difficulties could be avoided.