Peregrine Falcons are back for the winter

Peregrine Falcons are back at Hanoi and roosting on the higher buildings of the city. But the guy below prefers the fresh air of the countryside; it has chosen an electricity pylon along the Red River, just above my favorite mudflats :((

It's a large bird, so I'm pretty sure it's a female*.

Similar to the one I photographed in January last year (see this post) - note very pale underparts with unbarred belly (barring restricted to flanks and thighs). 

Could it be that this bird is the subspecies calidus ? This subspecies breeds in the Arctic tundra and is completely migratory - very long distance migrant, travels south in winter as far as South Asia and sub-Saharan Africa. According to literature, the very similar japonensis subspecies is noticeably darker above, has usually wash pale pinkish breast (pure white breast in calidus), broader moustachials and heavier spotting and barring on the belly and flanks (japonensis show much more extensive barring starting from lower breast, while calidus has more restricted area of barring, mostly at the thighs).

I'd be interested to hear views on this bird.

*well, considering the fact calidus is a large-sized Peregrine, that's merely speculation...

Calidus Peregrine candidate