Étude du régime et de la sélectivité alimentaire du grand cormoran (Phalacrocorax carbo) sur le lac Kivu (R.D. Congo)

This contribution intends to give a preliminary view of the diet of the Cormorant on the lake Kivu. Fifty pellets were collected from August to
October 2004 in a colony situated in Bukavu and analysed. A reference collection of fish skull bones was also prepared and correlations
between the length of some characteristic bones and the total length of the fish were computed, allowing the assessment of the length of each
prey identified in the pellets. The cormorants eat mainly Haplochromis species (either in relative abundance or occurrences) but the biomass
intake is dominated by the genera Tilapia and Oreochromis (together: 65 %). The importance of catfish (Clarias sp.) or barbels (Barbus sp.)
is very small (< 4%, whatever the expression of the results). The sardine Limnothrissa miodon appears in 1 out of 5 pellets but its
contribution in terms of biomass is negligible. Comparing the diet with the available resources, it appears that the cormorant is an
opportunistic predator, taking almost all the available taxa (except Raiamas moorii) without selecting a particular one, except the big
cichlids (genus Tilapia and Oreochromis). However, more than 90% of its preys are small fish measuring less than 10 cm.