Olive-backed Sunbirds moulting

“I am posting more pictures of Olive-backed Sunbirds (Cinnyris jugularis ornatus). These were taken at a Rest Stop along our major North-South Highway.

“I am posting them to ask a question. I am not well versed with bird morphology/development (unlike paediatrics). Occasionally I see, what I presume to be, new feathers developing on birds. These look like the shafts of the feather.

“I wonder if these are what is called ‘pin feather’ (i.e. developing feathers on a bird) Wiki says: ‘a new feather during the bird’s infancy, or grown to replace one from moulting.’ Pin feathers are supposed to be blood filled and look like a feather shaft.

“The ones on these birds look like there is a waxy coating over the new feather. Again from Wiki ‘As the pin feather grows longer, the blood supply is concentrated in only the base of the shaft, and the tip of the shaft encases the feather itself, in a waxy coating. As moulting birds preen, they remove the waxy coating, and the feather unfurls.’

“This was family of at least three. The first 2 posts (top row) show an adult male moulting with lots of ‘shafts’ especially in the head and face region. The 3rd posting (bottom row, left) shows an immature male moulting into an adult with shafts. The 4th (bottom row, right) a very bedraggled adult female (?pressures of being a parent) with some moulting.”

Dato’ Dr Amar-Singh HSS
Perak, Malaysia
23rd October 2010

Note: According to The Ornithologist’s Dictionary (J Erritzoe, K Kampp, K Winker & C B Frith, 2007, Lynx Edicions, Barcelona): A pin feather is a growing feather still enclosed in its protective waxy sheath.

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