Olive-backed Sunbird Cinnyris jugularis flammaxillaris – pectoral tuft

posted in: Morphology-Develop., Sunbirds | 0

“I observed an adult male Olive-backed Sunbird (Cinnyris jugularis flammaxillaris) male feeding on one of its favourite household nectar sources, Devil’s Backbone (Pedilanthus tithymaloides, now called Euphorbia ithymaloides). I was fortunate to image the display of the pectoral tufts that were directed at myself (above, below).

Pectoral Tufts in Sunbirds (and Spiderhunters/Flowerpeckers)
“Some have suggested that only a few sunbirds have pectoral tufts. But Cheke, Mann and Allen 2001, in their comprehensive account on Sunbirds, state: ‘Many sunbirds, spiderhunters and flowerpeckers have pectoral tufts – groups of elongated feathers emanating from the sides of the chest not from the underwing-coverts. These tufts are usually brightly coloured, often yellow, red or orange in sunbirds and spiderhunters, but white in flowerpeckers, and are prominent in displays. They are often concealed beneath the wings on perched birds.’

“I did an image and document search online, and many sunbirds have pectoral tufts. See the list below (not exhaustive); the vast majority are from the African continent (southern). Some have yellow-orange, other yellow-scarlet and some scarlet pectoral tufts. Note that Cheke, Mann and Allen 2001 notes pectoral tufts in many sunbirds but does not record them in some of the species I identified online. Even our local Brown-throated Sunbird male has pectoral tufts but they are hard to spot because they are yellow tufts that blend-in with the yellow of the breast (see my reference Amar-Singh HSS 2017).

List of Sunbirds (males) with pectoral tufts:
1. Olive-backed Sunbird Cinnyris jugularis
2. Brown-throated Sunbird Anthreptes malacensis malacensis
3. Loten’s Sunbird Cinnyris lotenius
4. Purple Sunbird Cinnyris asiaticus
5. Variable Sunbird Cinnyris (Nectarinia) venustus
6. Grey sunbird Cyanomitra veroxii
7. Malachite Sunbird Nectarinia famosa
8. Red-tufted (Scarlet-tufted) Sunbird Nectarinia johnstoni
9. Mouse-coloured Sunbird Cyanomitra verreauxii
10. Reichenbach’s Sunbird Anabathmis reichenbachii
11. Cameroon Sunbird Cyanomitra oritis
12. Olive Sunbird Cyanomitra olivacea
13. Blue-headed Sunbird Cyanomitra alinae
14. Seychelles Sunbird Cinnyris dussumieri
15. Carmelite Sunbird Chalcomitra fuliginosa
16. Ursula’s Sunbird Cinnyris ursulae
17. White-breasted Sunbird Cinnyris talatala
18. Oustalet’s Sunbird Cinnyris oustaleti
19. Orange-tufted Sunbird Cinnyris bouvieri
20. Palestine Sunbird Cinnyris osea
21. Congo Sunbird Cinnyris congensis
22. Splendid Sunbird Cinnyris coccinigastrus
23. Johanna’s Sunbird Cinnyris johannae
24. Black-bellied Sunbird Cinnyris nectarinioides
25. Lina’s Sunbird Aethopyga linaraborae
26. Greater double-collared sunbird Cinnyris afer
27. Southern Double-collared Sunbird Cinnyris chalybeus
28. Miombo double-collared sunbird Cinnyris manoensis
29. Collared sunbird Hedydipna collaris
30. Western violet-backed sunbird Anthreptes longuemarei
31. Plain-backed sunbird Anthreptes reichenowi
32. Amethyst sunbird Chalcomitra amethystine
33. Neergard’s sunbird Cinnyris neergardi
34. Crimson-backed Sunbird Leptocoma minima (pointed by Krys from a recent image)

The Function of Pectoral Tufts in Sunbirds
“The fact that many sunbirds have pectoral tufts (some possibly yet unrecognised/documented) suggests that have a function. That it exists predominantly in males (a minority of females have them as well) suggest an important role in courtship. Wells 2007 describes this role in the Olive-backed Sunbird. I have personally seen this courtship behaviour a number of times where the usually concealed apricot-orange pectoral tufts are extended or displayed. The male flits from branch to branch, from tree to tree, loudly calling, while the female follows to watch the display. The pectoral tufts are kept fully erect throughout the period of display even when flying from tree to tree. Similar courtship displays have also been described by other local observers, see Tsang, Wang & Wee 2008. Evans & Hatchwell 1992 describe the important role of pectoral tufts in territory defence in Nectarinia johnstoni. Wellmann & Downs 2010 describe the nocturnal pectoral tuft display in Nectarinia famosa. They say ‘Most male southern African sunbirds have pectoral tufts, although the function of these is not always understood. We examined nocturnal tuft display in male malachite sunbirds and found that they display their pectoral tufts almost continuously throughout the night, whilst asleep. We suggest the possible function of this behaviour and suggest that these tufts might be a deterrent to predators, as they look like ‘eyes’ in the dark.’

Why did the Olive-backed Sunbird display its pectoral tufts to me?
“The bird was calmly feeding on the nectar of Euphorbia ithymaloides until I started watching and taking some images from the car. I was very close to the bird, approximately 3 meters. There were no other sunbirds nearby. This went on for about 1 minute. The bird then turned to face me, extended its pectoral tufts and called loudly while flapping it wings. Most of the time it looked me straight in the face and even extended the tongue out. It did not look pleased. Occasionally it closed the wings but maintained the pectoral tuft display (above, below). This went on for ~20 seconds and then it left abruptly. I suspect it had had enough of me watching it and this was a territorial display against me. A brave little bird.”

References:
1. Robert A Cheke, Clive F Mann, Richard Allen 2001. Sunbirds: A Guide to the Sunbirds, Flowerpeckers, Spiderhunters and Sugarbirds of the World. Helm Identification Guides
2. Amar-Singh HSS 2017. A close look at the Brown-throated Sunbird LINK.
3. DR Wells 2007. The birds of the Thai-Malay Peninsula: Vol. 2 (Passarines). Christopher Helm, London.
4. KC Tsang, LK Wang & YC Wee 2008. The olive-backed sunbird, Cinnyris jugularis Linnaeus, 1766 and its pectoral tufts. Nature in Singapore 1:207-210.
5. Matthew R Evans, Ben Hatchwell 1992. An experimental study of male adornment in the scarlet-tufted malachite sunbird: I. The role of pectoral tufts in territorial defence. Behavioral Ecology and Sociobiology 29(6):413-419.
6. Andrea E Wellmann, Colleen T Downs 2010. Nocturnal Pectoral Tuft Display in the Malachite Sunbird. African Zoology, 45(2):342-348.

Dato’ Dr Amar-Singh HSS
Ipoh, Perak, Malaysia
1st January 2019

Location: Ipoh, Perak, Malaysia
Habitat: Urban environment

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