Failed Olive-backed Sunbird nesting

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The nesting of the Olive-backed Sunbird (Nectarinia jugularis) has been well documented locally HERE, HERE, HERE and HERE.

This post by Teo Lee Wei & K documents the failed nesting through a series of video clips that provide details of the adult sunbirds’ behaviour before and during incubating. The adults finally abandoned the nest after the eggs failed to hatch.

The beginning of the video above shows the adult male calling, his orange pectoral tufts displayed, indicating courtship LINK. This was documented earlier and the male was not the one that paired up with the female building the nest. The remaining of the video shows the female building their nest in a Dutchman pipe’s vine (Aristolochia gigantea) about one metre from the ground. Nest building was frenetic, as shown in the video below. The female entered the nest for a fleeting moment and came back with fresh nesting material every one to two minutes. It had an extra chamber above the egg laying chamber and lacks the usual overhanging canopy over the entrance. The white fluffy polyester fibres used to stuff pillows, dried lallang grass fluff (Imperata cylindrica) and dried Dutchman’s pipe leaves were used to construct this nest.

Throughout the nest building period the female was always busy at work. The adult male was heard singing nearby. The male was seen making a quick cursory check of the nest two days before the female laid her egg (below).

The female sat in her nest restlessly, preened herself and adjusted her egg as if trying to find the most comfortable position (below). Only one egg was laid. She was curious and still took a lot of interest in her surroundings. She also panted as it was a hot day and the haze had enveloped Singapore at full force – see HERE. The Spotted Doves (Streptopelia chinensis) were cooing loudly in the background.

The bird abandoned the nest after 24 days of incubation. Sunbird eggs typically hatch after 14 days of incubation. The egg, on close inspection, was found to be leaking and smelly (below). The shell was thin and papery, tearing easily at the point where a tiny hole was seen. The leaked contents showed a completely broken egg yolk with some black bits. There was definitely no embryo.

Teo Lee Wei & K
Singapore
October 2013

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