Yellow-eared Spiderhunter: 2. Nesting

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Dato’ Dr Amar-Singh HSS’s earlier account on the Yellow-eared Spiderhunter (Arachnothera chrysogenys chrysogenys) nest building activities LINK attracted the attention of Dr David Wells who commented:

“Most interesting, but you must eliminate the possibility of a spiderhunter poking about in some other bird’s construction looking for food or for material to take elsewhere. This structure is so unlike any Arachnothera nest that I know or have ever seen a description of that you definitely need direct, corroborative evidence of actual use. Any chance of return visits? Curious that your picture of the bird in the cavity shows a plain green rather than dark-speckled forecrown – expected in an immature rather than a breeding adult. Bit of a mystery here.”

Dr Amar-Singh responded: “Firstly I must say, as I mentioned earlier, that there is no doubt that this is a nest of a Yellow-eared Spiderhunter. I observed more than 40 nest visits bringing material as well as nest construction activities. No other birds approached.

“I must say I was as surprised as yourself. When a Yellow-eared Spiderhunter carrying nesting material first disappeared into the top of this high tree I dismissed it as a diversion. But when it happened again I spotted this structure and then watched nesting building activities over two hours.

“Yes, agree that I will have to see that adults are actually incubating and rearing young to confirm the nest and will try more visits. But the volume of construction activities is rather strong evidence.

“I will also try and see if it is only two birds or more are involved (the juvenile).

”I considered 3 possibilities while watching:
a. There is more than one type of nest construction by this species – under leaves as well in hanging structures.
b. Or this is an aberrant design learnt perhaps from sunbirds.
c. Or prior observations were inaccurate, as you have pointed out in you work, and this could be the definitive nesting design.

“Among the nesting material brought over the two hours include: spider web (above – more than 1/3 of visits), dried leaves,

“…dried ‘veins’ of leaves (above),

…moss (above), dried fungi and netted ferns/fungi,

…and dried Dragon’s Scale Fern (Pyrrosia piloselloides) (above).

On 29th and 31st July 2014, Dr Amar-Singh made two more visits to the spiderhunter’s nesting site and wrote: “Dr David Wells pointed out that ‘DNA suggests this bird’s nearest relative is the Naked-faced Spiderhunter of the Philippines. Would be worth a search to see if the latter’s nest has been described.’ I looked up images and reports on Naked-faced Spiderhunter nests and found only one by Con Foley HERE. Also available on Oriental Bird Images. These two nests look very similar and it is very likely that both these two spiderhunters do not nest under leaves.

“The nest is now complete and better developed (top). Both parents are actively incubating. I have noted two incubation swaps between the pair over the space of 2 hours.”

On 5th August 2014, Dr Amar-Singh spent another 2 hours at the site, intermittently. “Incubation was still in progress with very few change-overs (saw only 2).

“This is possibly the first documentation of the nesting of this bird.”

Dato’ Dr Amar-Singh HSS
Ipoh, Perak, Malaysia
July 2015

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