Australasia - its impressive adaptive radiation of honeyeaters (Meliphagidae) notwithstanding - lacks any true counterpart for the typical sunbirds (e.g. Nectarinia) of Africa and India
I define 'typical sunbirds' as follows:
- small body size (body mass 8-14 g),
- long beak ( - mm),
- tubular tongue,
- iridescent plumage, at least in males in breeding condition,
- a diet of mainly nectar, taken while perching rather than while hovering, and
- conformity, morphologically and behaviourally, to a syndrome of ornithophilous pollination of plants with bright-hued, tubular flowers (https://en.wikipedia.org/wiki/Ornithophily).
Any naturalist living in Africa and on the Indian subcontinent is likely to be familiar with at least one species of typical sunbird. This is because typical sunbirds
- are widespread from the southern tip of Africa to southeast Asia,
- consist of several genera and many spp.,
- are 'flashy' (visually conspicuous in a glittery way) in colouration and activity, and
- tend to be associated with showy (bright-hued) flowers/blooms.
It is reasonable to expect that at least one species of typical sunbird would occur in Australasia. This is because
- several genera of Nectariniidae occur East of Wallace's Line,
- one species of Nectariniidae occurs in Australia,
- Meliphagidae, which are associated with ornithophily, have undergone an extreme evolutionary radiation in Australasia, and
- certain meliphagids qualify for some of the criteria listed above for typical sunbirds.
Furthermore, many naturalists with some knowledge of the intercontinental similarities and differences in avifaunas, if asked 'are there any counterparts for typical sunbirds in southern Africa?', would probably reply 'yes'. This would be based on general impressions, and the overall interpretations that have tended to prevail in the formal and semi-popular literature.
However, my close scrutiny refutes the reasonable expectation. There is, in fact, no 'typical sunbird' in Australia or elsewhere in Australasia, whether in the typical family (nectariniids) or by virtue of evolutionary convergence.
This is because
- the Australian species of nectariniid depends on spiders rather than nectar, and tends to avoid pollinating the flowers from which it 'robs' nectar,
- the closest meliphagid counterparts for typical sunbirds fall short in lacking iridescent plumage, and
- the tongue of meliphagids are brush-tipped rather than tubular.
Within Australia, three genera in particular have produced birds that are 'so near and yet so far' w.r.t. having converged with typical sunbirds. I refer to the following spp. in particular:
- Lichmera indistincta (https://www.inaturalist.org/taxa/12526-Lichmera-indistincta),
Typical sunbirds in Africa:
- Anthobaphes violacea https://www.inaturalist.org/taxa/145130-Anthobaphes-violacea
- Chalcomitra 7 spp. https://www.inaturalist.org/observations?subview=map&taxon_id=144401&view=species
- Nectarinia 6 spp. https://www.inaturalist.org/observations?subview=map&taxon_id=13274&view=species
Typical sunbirds in peninsular India:
- Leptocoma zeylonica https://www.inaturalist.org/taxa/145146-Leptocoma-zeylonica
- Leptocoma minima https://www.inaturalist.org/taxa/145147-Leptocoma-minima
- Aethopyga siparaja https://www.inaturalist.org/taxa/204458-Aethopyga-siparaja
- Aethopyga vigorsii https://www.inaturalist.org/taxa/145204-Aethopyga-vigorsii
- possibly Cinnyris lotenius (https://www.inaturalist.org/observations?subview=map&taxon_id=145203&view=species)
- possibly Cinnyris asiaticus (https://www.inaturalist.org/taxa/145193-Cinnyris-asiaticus)
Typical sunbirds East of Wallace's Line:
- Aethopyga siparaja (Sulawesi) https://www.inaturalist.org/taxa/204458-Aethopyga-siparaja
- Aethopyga duyvenbodei (Sangihe, immediately north of Sulawesi) https://www.inaturalist.org/taxa/13420-Aethopyga-duyvenbodei
Leptocoma aspasia (https://www.inaturalist.org/taxa/979764-Leptocoma-aspasia) of New Guinea belongs to a genus that contains typical sunbirds in India. However, this species is relatively generalised in diet, with invertebrates and fleshy fruit-pulp apparently being equally important.
