Largest bird egg relative to body size

The brown kiwi (Apteryx australis) of New Zealand lays the largest eggs relative to its body size. One female kiwi weighing 1.7 kg (3 lb 12 oz) laid an egg weighing 406 g (14 oz), which is almost one quarter of her total body mass, and weights of up to 510 g (1 lb) have been reliably reported for other kiwi eggs.