It is closely related to the streaked fantail of the rest of Fiji, and forms a superspecies with the numerous island species of fantail ranging from the Solomon Islands (the brown fantail) to Samoa (the Samoan fantail).

The Kadavu fantail is restricted to tropical moist lowland forests, where it feeds by flycatching for insects.

It sometimes joins mixed-species feeding flocks with Polynesian trillers, Fiji bush warblers and silvereyes.

The breeding season is October and November.

Kadavu fantail (R. personata) forms a superspecies with:[2]