Habitat and nest-site partitioning in splendid and variegated fairy-wrens (Aves : Maluridae)

Abstract

Territory size, interspecific interactions, foraging behaviour, habitat use, and nest placement were examined in sympatric populations of splendid (Malurus splendens melanotus) and variegated (M. lamberti assimilis) fairy-wrens. Although these species have similar patterns of life history and biology, they utilise different microhabitats within overlapping territories. Splendid fairy-wrens spent more time on the ground and in open areas, whereas variegated fairy-wrens generally preferred higher and more protected locations. The two species exhibited a similar pattern of separation with respect to foraging behaviour, as splendid fairy- wrens mainly foraged on the ground whereas variegated fairy-wrens preferred bushes. They also partitioned nesting habitat, with splendid fairy-wrens building nests in areas with a greater density of trees than variegated fairy-wrens. Further, splendid fairy-wrens built nests in larger shrubs and farther from the edge of these bushes than variegated fairy-wrens. We suggest that these differences in habitat use decrease interspecific competition between the two species.