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Food niche segregation between the Malachite Kingfisher, <i>Alcedo cristata</i>, and the Pied Kingfisher, <i>Ceryle rudis</i>, at Lake Nokoué, Bénin
Abstract
Several species of kingfisher
occur on Lake Nokoué, southern Bénin, including Malachite (Alcedo cristata)
and Pied Kingfishers (Ceryle rudis). Here, we compare their diet and
estimate the degree of overlap in food niche by analysing contents of
regurgitated pellets collected near nesting sites of Pied Kingfishers or inside
the nest chambers of Malachite Kingfishers. Characteristic fish skull bones
were identified using a reference collection of local fish skeletons. Malachite
Kingfishers feed most frequently on fish that occur around floating vegetation,
mainly Kribia sp. (56%), Hemichromis fasciatus (28%) and Sarotherodon
melanotheron (8%). Important differences were found between different
pairs, and between adults and nestlings, the latter being fed almost
exclusively on Kribia sp. Larger fish are fed to nestlings than are
eaten by the adults. Pied Kingfishers prey upon 14 different fish species, some
of them being caught in the pelagic region of the lake, particularly clupeids
taken by hovering. By comparison with Malachite Kingfishers, Pied Kingfishers
feed on a wider diversity of prey, and take larger fish, so that the dietary
overlap between the species is relatively low (O = 0.181).
Ostrich 2004, 75(1&2): 32–38
occur on Lake Nokoué, southern Bénin, including Malachite (Alcedo cristata)
and Pied Kingfishers (Ceryle rudis). Here, we compare their diet and
estimate the degree of overlap in food niche by analysing contents of
regurgitated pellets collected near nesting sites of Pied Kingfishers or inside
the nest chambers of Malachite Kingfishers. Characteristic fish skull bones
were identified using a reference collection of local fish skeletons. Malachite
Kingfishers feed most frequently on fish that occur around floating vegetation,
mainly Kribia sp. (56%), Hemichromis fasciatus (28%) and Sarotherodon
melanotheron (8%). Important differences were found between different
pairs, and between adults and nestlings, the latter being fed almost
exclusively on Kribia sp. Larger fish are fed to nestlings than are
eaten by the adults. Pied Kingfishers prey upon 14 different fish species, some
of them being caught in the pelagic region of the lake, particularly clupeids
taken by hovering. By comparison with Malachite Kingfishers, Pied Kingfishers
feed on a wider diversity of prey, and take larger fish, so that the dietary
overlap between the species is relatively low (O = 0.181).
Ostrich 2004, 75(1&2): 32–38
