Can Geographical Distance influenced the Differences in Birds Features ?

We may all appear different from the outside but deep inside i believe we are all the same - ever compassionate and merciful. In the avian world, geographical distance may have some effect on some birds plumage thus creating more subspecies. This can only be determined / confirmed if the subtle differences occur over a period of time. Recently i came across some birds from different states which show some differences in their outlook despite been from the same species.

I start with Mr Abbott's Babbler (M. abbotti):

The photo below of an Abbott's Babbler was taken in Kedah. Its flank appear more buffy while the orbital ring around its eyes were less prominent as compared with the one i saw in Penang mainland.

Below are those from Penang mainland

Despite the above differences, i would also not discount that they could be from different gender or age group. More observations are required.

Next is the Mangrove Flycatcher (C. rufigastra):

The photo below depicts a Mangrove Flycatcher taken at Penang mainland.

and this one below was taken in Kedah recently

Again although both the above flycatchers were male but the differences (color of its legs, throat and forehead) could be due to age variation or the different timing of moulting (of their feathers).

Here is the very common "White-throated Kingfisher" (H. smyrnensis):

The above photo was taken in KL. It looks like your typical white-throated kingfisher.

This one below was taken in Perlis. It appears darker and with a brighter turquoise above and on wing coverts.

Could it be from a different Ssp?

Science and birds are inextricable just like a lady and her lipstick but when you use Science against humanity its no longer a science !