THE TUATARA. 2J 



PRELIMINARY NOTE ON THE DEVELOPMENT OF THE 



TUATARA (Sphenodon punctalum).* 



BY PROF. A. P. W. THOMAS, M.A., F.G.S., F.L.S., University College, 

 Auckland, N.Z. 



A grant was made by the Royal Society in the year 1884 to Pro- 

 fessor T. J. Parker, of Dunedin, for the study of the development of 

 Apteryx, Sphenodon, and CaMorkynchus. As Sphenodon does not occur 

 near Dunedin, hut is found chiefly on outlying islands belonging to the 

 province of Auckland, at the opposite end of the colony, Professor 

 Parker invited me to join him in the investigation of this form. 



We gathered from what had been written on the natural history of 

 the tuatara, as well as from oral information obtained from those who 

 were best acquainted with the New Zealand fauna, that the month of 

 February was probably the time at which the tuatara bred. 



We therefore started from Auckland at the beginning of February, 

 1885, for what appeared the most promising hunting-ground — the 

 island of Karewa, some ten miles from Tauranga, in the Bay of Plenty. 

 Mr. A. Reischek, a naturalist well known by his researches on the 

 natural history of New Zealand, who had already had opportunities of 

 observing the tuatara, was good enough to accompany us. 



The island of Karewa is situated some four miles from the main- 

 land ; it is little more than a rock which rises with precipitous sides 

 high above the sea. At one spot only can a landing be effected, as the 

 island is exposed to the ocean swell rolling in from the open Pacific, 

 whilst the shores are for the greater part formed by unscaleable cliffy of 

 rhyolitic rock. Our first attempt at landing was frustrated by the 

 swell, but a day later a second attempt was successful. 



The vegetation on the island is largely composed of small karaka 

 trees and thickets of eoprosma. The light, loose soil between the roots 

 of trees and the rocks is mined by countless burrows, in which live 

 mutton-birds (Puffinus tenuirostris) and tuataras. 



On the " Chicken Islands " the tuataras have been described by 

 Mr. Reischek as living with certain other sea-birds, namely, another 

 species of Puffinus (P. gavius) and two species of Procellaria. This 

 has been cited in ' Nature' t as an interesting case of commensalism, and 

 and it is there stated that the birds " live in holes dug out by the 

 tuataras and keep apparently on the best terms with them." It is 

 stated that the tuatara generally lives on the right and the sea-bird on 

 the left of the inner chamber. 



I believe it is quite a mistake to suppose that any friendly relation 

 whatever exists between the tuataras and the birds, and that here, as 

 in the somewhat similar case of the prairie dog and rattlesnake, the idea 

 of friendliness is quite out of place. It is true that the tuatara some- 

 times makes use of the burrows of the mutton-bird (though I have 



*From the "Proceedings of the Royal Society," Vol. 48. 



t October 19th, 1882. See also "Transactions of the New Zealand Institute," 



Vol. XIV., p. 274. 



