Kingfishers inhabit slow-moving, shallow rivers or streams which are clean enough to support abundant small fish.
Fast-moving streams and polluted waters do not contain enough available fish, and hence do not contain kingfishers. Branches overhanging shallows make essential fishing perches.
Kingfishers eat mainly fish, chiefly minnows and sticklebacks, but they also take aquatic insects, freshwater shrimps and tadpoles etc to top up their diet. They prefer fish about 23 mm in length, but can handle anything up to 80mm long.
An ideal fishing spot is a firm perch overlooking a clear, shallow pool of water. Once the bird has located a suitable prey and assessed its depth, it dives. At the entry into water, its beak is opened and its eyes closed by the third eyelid. The bird is effectively blindfolded as it catches the fish.
On return to the perch, it repeatedly strikes the fish against the perch to kill it. Only then will the spines in the fins of some species such as sticklebacks relax to allow the bird swallow it, head first. Each bird must eat at least its own bodyweight of fish each day.