Unexplained observations of an Olive-backed Sunbird Cinnyris jugularis nesting.
By Alfred Chia.
I had written briefly on my Facebook page about the nesting of an Olive-backed Sunbird Cinnyris jugularis along the corridor of my flat. The nest was however built out-of-sight and out-of-reach and hung from one of my plant which overhangs beyond the parapet wall. You will not be able to see it unless you take the trouble to peer over the wall.
Briefly, the female sunbird started constructing the nest on or before 10 February 2020. On 16 March, the female started occupying the nest. From 8 April onwards, the male was observed bringing food to the nest very frequently, each time perching on another plant that is visible to me as I stand within my house, before it flies into the nest to feed its fledgling. Out of two chicks, one survived, as is usual. This chick fledged on 18 April, about twelve days after hatching. After this, the fledgling was not seen but the two parent birds still came to my plants sporadically.
On 21 April, something unexpected (at least to me) happened. I had peered beyond the parapet wall at 1100 hours just to see if there is still any activity at the nest. No activity was seen, as has been the case since the chick fledged on 18 April but it was noticed that the nest opening was a wee bit messed up such that the opening was partially blocked. At 1315 hours, I went back out again to have a look. I was shocked at what confronted me. The nest was missing! I looked at the small ledge that was directly below the area where the nest was at formerly to see if it had dropped onto it. Besides some remnant dried leaves that were already there for some time, the nest was nowhere to be found. Baffled, I took the lift to the ground floor to further check if the nest had dropped there. Again, it was not found.
A flurry of questions immediately ran through my mind. What happened to the nest? Did the sunbird remove the nest intentionally? Or was it relocated? Why did they do it? Where could it have taken it to? Could it have been the female sunbird who remove it? Could it have carried the entire nest structure away in one fell swoop because the remnant dried leaves on the ledge does not indicate that it had increased exponentially?
I had a previous unexplained experience of an incomplete Olive-backed Sunbird nest missing too. This was on a plant along the corridor. It was halfway through construction when suddenly it just disappeared. It was a clean act too as the floor directly below the nest was clean and devoid of any nesting material. At that time, I had even surmised that my friendly block cleaner could have taken it off my plant as the nest building can be very messy with bits of the material being dropped onto the floor constantly. About two months after this incident, I had my niece, who lives in Yishun, coming up to me to ask if sunbirds are capable of removing nest after painstakingly building it. Hers was also in the midst of being constructed when she realised that it was missing the next day. When I ask if it could have been the block’s cleaner who had removed it, she replied that the cleaner hardly ever cleans the corridor.
A check through my Sunbirds, Flowerpeckers, Spiderhunters & Sugarbirds monograph by Robert A. Cheke & Clive F. Mann reveal no such information on nest removal or relocation. A check through the internet & other resources did not help either.
It will be interesting to know if any of our readers, birders or photographers have noted such behaviour from an Olive-backed Sunbird before. I’d be glad to hear from you. Additionally, it may be well worth to follow-up on future nesting of this species if you come across it – both pre and post-nesting.