The image on the left shows four Red Junglefowl eggs together with a larger chicken egg at the top and a hybrid (Red Junglefowl x domestic chicken) egg below for comparison. The colour of the hybrid egg is between that of the chicken egg (top egg) and the juglefowl’s. The hybrid egg was not fertilised (at least field ornithologist Wang Luan Keng could not see the embryo) and had a thicker wall than the white eggs. The dimension of the hybrid egg is 47.5 x 35.0 mm. On the other hand, the junglefowl eggs were all fertilised and their embryos were very small, although two were slightly larger.
The creamy white eggs of the junglefowl are glossy and the mean length x breadth = 45.1 x 33.9 mm (43.4 x 33.5; 45.1 x 33.9; 44.9 x 32.7; 46.6 x 35.0 and 45.4 x 34.6).
The five junglefowl eggs came from a single clutch, laid on a scrape of a nest on the ground overgrown with tall grass. Apparently the incubating bird flew off suddenly when disturbed, thus exposing the location of the nest.
The eggs are now with the Raffles Museum of Biodiversity Research, National University of Singapore.
Tan Teo Seng, Wang Luan Keng & YC Wee