Review of gene movement by bats and birds and its potential significance for eucalypt plantation forestry

Pollen- and/or nectar-feeding lorikeets and bats and nectar-feeding honeyeaters, while less frequent visitors to eucalypt flowers than insects, may make a unique contribution to eucalypt population structure because of their capacity to move pollen large distances. Birds and bats may travel upwards of 50 km day–1 during feeding, and further during migration or feeding bouts over several days. Limited data suggest that they carry viable pollen. Several eucalypts have adaptations favouring bird pollinators, while some species, particularly Corymbia spp., have adaptations commonly found among plants pollinated by bats and other nocturnal visitors. Bats may have the capacity to carry viable pollen over greater distances than birds. We suggest that the effect of pollen transfer by birds and bats on the genetic structure of widespread eucalypt species is potentially greatest in fragmented forests where these animals can traverse gaps of several kilometres between discontinuous stands. Greater understanding of pollen movement by birds and bats in natural eucalypt forest is a prerequisite to understanding the potential for gene movement from commercial eucalypt plantations into native forests.