In my opinion, and searched on the internet, it is not the saker falcon.
On the belly, we can see there are many streaks. It suggested that it might be a juvenile saker if it is.
Then the leg color tell us it is not saker because the juvenile saker has pale yellow or grey leg color.
So, it is probably the peregrine falcon for me.
In addition, as I am one of the watcher yesterday=] I remember it flew with a relatively flat posture/ shape.
But after I searched on the internet, I can see there are some differences between these two falcon.
Saker's tail will intend to push down when it is gliding and the wings of it has a small angle.
So, the overall shape of it is no as flatted as peregrine.
I hope my interpretation is right and I just tell what I have read on the internet=]
Welcome for correction and discussion, Thank You!
