aim by minimizing light refraction off water or by creating a sightline when the bird is fishing . Another school of thought holds that the white patches enable chicks to see a parent ’ s food-bearing beak in the dark ( Eastman 1999 , 107 and 108 ). Understandably , some of these ideas relate to increasing the bird ’ s chances of obtaining food since kingfishers require optimum conditions for successful fishing .
Habitat and Feeding Two of these necessities for feeding are ready access to water and nearby perches , such as overhanging branches . As a result , kingfisher habitats include calm marine environments , estuaries , mangrove swamps , ponds , lakes , streams , and rivers . A kingfisher feeds by diving from a perch or by hovering over the water just before its dive , so it requires relatively clear or shallow water to be able to see its prey . Even if these conditions are met , less than half its dives are successful due to the opaque nictitating membranes that move into place to protect its eyes just as it hits the water ( Line 1995 ).
The kingfisher primarily pursues small minnow-like fish , but its diet can also include invertebrates , such as crayfish , frogs , small snakes , and aquatic insects . More rarely , it may eat young birds , small mammals , and even berries . Scientists in Florida have observed an interesting commensal relationship between kingfishers and egrets . A kingfisher will hover over an egret while it is feeding so the kingfisher can zoom in and capture any prey the egret might miss . ( Eastman 1999 , 112 )
With prey in their beaks , kingfishers light on a nearby branch or rail and bang the fish or other food until it no longer resists . In the case of invertebrates , they may take them apart before eating . Fledglings have stomach acid that can dissolve undigestible parts . Once the birds fledge , they regurgitate any pieces of undigested prey in the form of pellets .
Feeding can take much of a kingfisher ’ s day under normal circumstances . However , the period from nesting through hatching and fledging places even more significant time and caloric demands on the birds , requiring strenuous fishing efforts by both members of a pair . In his own work , biologist Dan Albano observed , “ One mated pair cleaned out a pot of 50 fish in a day . They munch them like we munch Doritos .” ( as quoted in Line and Kuhn 1996 ).
Nesting and Mating The parental role takes every bit of energy that these small birds possess . The nesting period begins with the courtship ritual in which the male kingfisher feeds a fish to an interested female . The pair then selects an appropriate nesting site , typically a steep embankment of sandy or clay-like soil along
54 Naturally Kiawah