Nest size and location in relation to reproductive success and breeding timing of tree-nesting Great Cormorants

Nest size and location, breeding timing, and reproductive success were docu mented at a newly established colony of tree-nesting Great Cormorants (Phal acrocorax carbo) at Lake Naivasha, Kenya (0 degrees 49'S) in 1995. Reproduc tive success was significantly higher in canopy-top nests than in nests bel ow the canopy and there was a positive and significant relationship between nest size and reproductive success. Early-breeding. pairs preferentially l ocated their nests on the canopy top and built significantly larger nests t han later breeders. When the effect df breeding timing is taken into accoun t, the effects on reproductive success of nest size and location were not s ignificant.