In Zambia, four different kingfishers accompanied us down the Luangwa River. (Photographing from a small moving boat, when the bird is tiny, and perches only briefly, is a challenge, so some of these shots are not up to much,)
The tiniest was the Malachite Kingfisher, Corythornis cristatus, at about 13cm long:
The middle-sized ones were the Brownhooded Kingfisher, Halcyon albiventris, at 22cm, on the left below, and the Pied Kingfisher, Ceryle audis, at about 25cm, on the right:
(The guide was quite excited by this shot, he said it is very rare to get two different ones in the same shot! Sheer luck.).
And the biggest was the Giant Kingfisher, Megaceryle maximus, at about 45cm long. (I just love the scientific name, making it abundantly clear first in Greek and then in Latin that this is a BIG kingfisher!). This one is a male:
It was a mystery to me how they hunted in this river. The water is completely opaque with brown mud, but the guides told me that the birds see tiny disturbances of the surface, and go for that. It obviously works, there are lots of them.
Presumably the size range of the different species means they favor slightly different prey fish, and thus can all share the same waters successfully.
PS: For comparative purposes, the UK’s only kingfisher, Albedo atthis, is about 16cm long, intermediate between the Malachite and the Pied. The Belted Kingfisher, Megaceryle halcyon, of the Northeast USA is 28-25cm long, intermediate between the Pied and the Giant.