The Honeyeaters and Australian Chats are a large and diverse family of small to medium-sized birds most common in Australia and New Guinea, but also found in New Zealand and certain Pacific Islands. Several genera display hybridization.
The Helmeted Honeyeater (Lichenostomus melanops cassidix) is critically endangered and could be ‘genetically rescued’ by the closely related subspecies L. m. gippslandicus. Harrisson et al. (2016) find that gene flow from gippslandicus to cassidix has declined substantially relative to pre-1990 levels and argue that natural levels of gene flow between the two subspecies should be restored.
Examination of phenotypic variation of Black-eared Miner (Manorina melanotis) and Yellow-throated Miner (M. flavigula) revealed that these species were separable until 1950, when extensive habitat modification took place. After this event, the two taxa show a continuum of phenotypic traits between them, indicating hybridization (Clarke, Gordon & Clarke, 2001).
Two subgroups of honeyeaters of the Melidectes leucostephes – belfordi group are allopatric in New Guinea, but interbreed in a broad contact zone in the mountains of central New Guinea (Gilliard, 1959; Mayr & Gilliard, 1952).
The Sooty (Myzomela tristami) and Cardinal Myzomela (M. cardinalis) recently came into secondary contact on the Solomon Islands. A genetic study reported nuclear introgression from the native species (M. tristami) to the colonizing species (M. cardinalis) (Sardell & Uy, 2016).
Clarke, R. H., Gordon, I. R. & Clarke, M. F. (2001). Intraspecific phenotypic variability in the black-eared miner (Manorina melanotis); human-facilitated introgression and the consequences for an endangered taxon. Biological Conservation 99, 145-155.
Gilliard, E. T. (1959). The ecology of hybridization in New Guinea honeyeaters (Aves). American Museum novitates; no. 1937.
Harrisson, K. A., Pavlova, A., da Silva, A. G., Rose, R., Bull, J. K., Lancaster, M. L., Murray, N., Quin, B., Menkhorst, P., Magrath, M. J. L. & Sunnucks, P. (2016). Scope for genetic rescue of an endangered subspecies though re-establishing natural gene flow with another subspecies. Molecular Ecology 25, 1242-1258.
Mayr, E. & Gilliard, E. T. (1952). Altitudinal hybridization in New Guinea honeyeaters. Condor, 325-337.
Sardell, J. M. & Uy, J. A. (2016). Hybridization following recent secondary contact results in asymmetric genotypic and phenotypic introgression between island species of Myzomela honeyeaters. Evolution 70, 257-269.