Honeyeaters of Australia: Convergent Evolution of Nectar feeders – Sunbirds, Hummingbirds & Honeyeaters

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“My wife and I visited Australia in September 2011 for a short holiday and we took the opportunity to do some bird watching in the nature parks around Melbourne, Victoria: the Dandenong Ranges National Park, Bunyip State Park and the beautiful Botanical Gardens at Melbourne. One group of birds that interested me were the Honeyeaters.

Convergent Evolution of Nectar feeders – Sunbirds, Hummingbirds and Honeyeaters

“Many of us are very acquainted with our local nectar feeders, the Sunbirds (Nectariniidae), and have heard of (or seen) the Hummingbirds (Trochilidae) of the Americas. But the Honeyeaters (Meliphagidae) of Australia and Pacific islands are less well known.

“The Sunbirds, Hummingbirds and Honeyeaters resemble each other in feeding behaviour and at times in appearance but are not related. The similarities are due to convergent evolution. ‘Convergent evolution describes the acquisition of the same biological trait in unrelated lineages” (Reference 1, 2, 5, 7).

What are the Honeyeaters?
“They consist of 182 species in 42 genera, almost all (with one exception) found east of the Wallace Line (Reference 3). About half are native to Australia and the rest the surrounding Pacific islands and New Zealand. It is interesting that the Australian chats also belong to the same family (Meliphagidae, honeyeaters category) and some, like the Crimson Chat, also take nectar (Reference 2).

Feeding Behaviour of Honeyeaters

“Honeyeaters, like Sunbirds, are important pollinators of many endemic plants. What is unique about the Honeyeaters is the evolutionary development of their tongue and beak. The tongue is long and has a brush-tip, i.e. it is frayed, fringed with bristles and works like a paint brush to soak up nectar by capillary action (Reference 2, 3, 4). See image of the tongues of Meliphagids found at Reference 5. Picture (left) shows Red Wattlebird (Anthochaera carunculata) feeding on nectar. ‘The upper mandible then compressing any liquid out when the bill is closed’ (Reference 3). Honeyeaters also have an ‘operculum over their nares to protect their nasal cavity from pollen’ (Reference 5). Like Sunbirds and Hummingbirds, the Honeyeaters also supplement their diet with insects and occasionally fruits. ‘The alimentary tract is also adapted for nectar in an arrangement that lets the liquid pass directly to the intestines but separating things that require more digestion, like insects caught during the feeding, to be retained in a separate chamber of the stomach’ (Reference 2). Although most cannot hover like the Hummingbirds, they can fly backwards because of their special wings (Reference 3).

“Apparently the different Honeyeater species compete for flowering plants and the larger, more gregarious ones tend to win out. The Little Wattlebird (Anthochaera chrysoptera), not so ‘little’ in size, tends to be particularly aggressive (Reference 6). Hence the smaller species, like Spinebills, tend to favour thick foliage plants where they can “hide out”.

Some Examples of Australian Honeyeaters
“(Images taken from nature parks around Melbourne, Victoria. Reference 6 for some details). Honeyeaters come in a variety of sizes, from small sunbird-like to medium sized birds (bigger than a myna or small dove). They are called by a variety of names depending on behaviour or characteristics: Honeyeater, Wattlebird, Friarbird, Spinebill, Miner, etc. When you first see many of them you do not expect them to be nectar feeders.

Red Wattlebird (Anthochaera carunculata) (above left)
“A ‘wattle’ is a fleshy growth hanging from the head/neck of birds. The Wattlebirds have brightly coloured wattles hanging from the cheeks, neck or throat. The Red Wattlebird, as can be expected, has red wattles hanging from the neck. It is a large slender bird, 33-37 cm long, heavily streaked and with a yellow belly, and quite noisy. It is one of Australia’s largest Honeyeater.

Little Wattlebird (Anthochaera chrysoptera) (above right)
“Although a Wattlebird, the Little Wattlebird lacks wattles. It is smaller at 27-35 cm, also finely streaked, largely brown and has a rufous wing patch seen in flight. As mentioned earlier it tends to be particularly aggressive towards other members of its species, a behaviour I observed when watching them feed in the same flowering bush. Also tends to be quite vocally aggressive (an edited call recording HERE).

New Holland Honeyeater (Phylidonyris novaehollandiae) (left)
“The New Holland Honeyeater (needs a better name) is a delightful, pretty Honeyeater with bright markings – a bright yellow wing patch with black and white markings, making it striking. It is a smaller bird at 16-20 cm and very active like our local Sunbirds, busy flitting from flower to flower. It also has a call closer to our sunbirds (call recording HERE).

White-plumed Honeyeater (Lichenostomus penicillatus) (below left)
“The White-plumed Honeyeater is a sweet looking bird that you would not consider as a nectar feeder at first sight (much the same with the others above). An olive- yellow bird with a white neck, 14-18 cm in size. Found (as we met it) in open forest near water or wet lands and particularly fond of the red gum trees. Quite active and fast and I got this image as it was subdued by the rain.

Eastern Spinebill (Acanthorhynchus tenuirostris) (below right)
“The Spinebills are birds that look more like I’d expect Honeyeater to be. They have a nice long, thin bill like Sunbirds or Hummingbirds. The Eastern Spinebill has beautiful plumage – a small rufous throat and nape, cinnamon belly with lovely black and white markings. Fast moving, can hover and the bill is suited to tubular flowers. 13-16 cm in size.

Bell Miner (Manorina melanophrys) (below left)
“A very unusual looking bird that we met, as expected in eucalyptus forests. It has a bright orange bill and feet with olive-green plumage. It is the appearance of the face that gives it an odd look (see images). I missed recording a call, but they are unmistakable – a bell like “tink”, which gives them their name. Hence heard more than seen. Size 17-20 cm. Tend to be quite sociable and live in colonies.

White-fronted Chat (Epthianura albifrons) (above right)
“As mentioned, the Australian chats also belong to the same family as honeyeaters – Meliphagidae. Some are Honeyeaters but the White-fronted Chat, mentioned here for completeness, is not. These birds tend to favour swampy or damp locations and we met many in wetland areas. A sweet, small bird (11-13 cm) having a white face, throat and belly with a black band across breast and nape. The female is browner.”

Dato’ Dr Amar-Singh HSS
January 2012

References:
1. Article on Convergent evolution from Wikipedia. Source: http://en.wikipedia.org/wiki/Convergent_evolution
2. Article by Don Roberson on Honeyeaters, revised 2008. Source: http://creagrus.home.montereybay.com/honeyeaters.html
3. Article on Honeyeaters from Wikipedia. Source: http://en.wikipedia.org/wiki/Honeyeater
4. Article on Honeyeaters from BIRD (Biodiversity Information, Resources and Data). Source: http://bird.net.au/bird/index.php?title=Honeyeater
5. “GrrlScientist”, 2008. When is a Honeyeater not a Honeyeater? The Tricks of Convergent Evolution. Source: http://scienceblogs.com/grrlscientist/2008/12/when_is_a_honeyeater_not_a_hon.php
6. Simpson and Day, 2010, Birds of Australia, 8th Edition.
7. Map of Life – “Hummingbirds, sunbirds and honeyeaters” 2012. Source: http://www.mapoflife.org/topics/topic_404_Hummingbirds-sunbirds-and-honeyeaters

One Response

  1. I live in Melbourne and enjoy looking at your site regularly. I found the write-up on Melbourne Honeyeaters interesting, and learned more about their digestive systems. Although they are attractive, New Holland Honeyeaters are quite aggressive too. Bell Miner colonies around Melbourne seem to be lessening and some work is apparently being done to work out why.

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