Giant bird of Madagascar

Press, Volume CXI, Issue 32589, 24 April 1971, Page 13

Giant bird of Madagascar

(Contributed by the Canterbury Museum)

A recent news item mentioned that on March 4 an egg of Aepyomis maximus was to be auctioned in London. The Canterbury Museum possesses one of these enormous eggs, and the cast of another but there is no space to display them at present.

Until we find an undoubted egg of the largest moa, Dinomis maximus, or its North Island counterpart, Dinomis giganteus, these Aepyomis eggs are the largest bird’s eggs known. The bird, of which there were several species, lived in Madagascar, and evidently, like the moa, survived until the coming of man, because legends about them survived among the Arabs. The “Arabian Nights Entertainment” refers to them as the “Roc”—more properly spelled “Rukh”— and one of them carried off Sinbad the Sailor on its back. The eggs are not often found whole, although in some species the shell was much thicker than the moa egg shell. They are found in a fossilised or sub-fossilised state.

The egg to be auctioned was stated to be 15in in length and 28in in girth. The Canterbury Museum egg is a little smaller. Its length is 11 5-Bin, the girth is 23in and the diameter 8 5-Bin. Our egg possibly belongs to another species. The Canterbury Museum specimen was obtained through the generosity of that great benefactor to our bird collection, Edgar F. Stead, who presented it in 1911. There are no particulars as to where he bought it X-ray photographs of some of these eggs have shown chicks inside them.

Size varied

The largest of these birds are estimated to have stood about 9ft high—the largest moa stood about 10ft in a normal position but both birds would have been able to crane their necks higher to reach a succulent branch.

As mentioned above, several species of Aepyomis have been described, and many more than are at present regarded as valid species. Lambrecht in his great “Handbuch der Palaeomithologio,” recognised four

species, Aepyomis maximus, A. Medius, A. hildebrandt, and A. gracilis. As with the moa the multiplicity of names formerly bestowed arose because of a lack of sufficient material with which to work, and a failure to realise that these birds varied greatly in size within any one species.

Remarkable bones I do not know a great deal about their habits, but would imagine that, like the various moa, they were herbivorous browsers on grasses, shrubs and trees. The shape and construction of the beak would suggest this. The pelvis bears a marked resemblance to that of some moa species but the most remarkable bones in Aepyomis are the sternum (breastbone) and the fused scapuo-cora-coids (shoulder-blade bones) which arise from the sternum. These are like enormously enlarged versions of the same kind of bones in the

kiwi, and are one of the most striking illustrations of convergent evolution known to me.

A “Museum of Nature” article is not the place for a detailed osteological comparison between Aepyornis and, say, Dinomis, but the general picture which emerges is of four species of very large flightless birds somewhat shorter than the moas but with heavier bones. They survived for over a million years (from some time in the Pleistocene and possibly much longer) in isolation in an island off the coast of Africa, until the coming of man. They must, in that time, have survived several changes of climate, so that their eventual extinction is probably to be attributed, as in many other cases, to man. At any rate it is a pity that these interesting birds, like their close cousins, the three species of Mulleromis, also of Madagascar, are no longer with us.—R.J.S.