Birds’ eggs, like the birds themselves, vary enormously in size. The largest egg from a living bird belongs to the ostrich. It is over 2000 times larger than the smallest egg produced by a hummingbird. Ostrich eggs are about 180 mm long and 140 mm wide and weigh 1.2 kg. Hummingbird eggs are 13 mm long and 8 mm wide and they weigh only half of a gram. The extinct Elephant Bird from Madagascar produced an egg 7 times larger than that of the Ostrich!

Relative Size
Although large birds lay larger eggs than do small birds, small birds actually have proportionately larger eggs. It takes 60 ostrich eggs to equal the weight of one ostrich but only nine hummingbird eggs to equal the weight of the Calliope Hummingbird. The birds that lays the largest eggs, relative to body size, are the kiwis of New Zealand. Kiwis are about the size of a chicken but lay eggs that are about 140 mm long and 90 mm wide, about three times the size of a chicken egg. It takes only four kiwi eggs to equal the weight of a kiwi. Fortunately, female kiwis lay only one and occasionally two eggs per year!
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