In a paper read before the Philosophical Institute of Canterbury, in 1871, † I offered the first account of the discovery of a few bones belonging to a gigantic bird of prey, which were obtained with a considerable quantity of Moa bones in the turbary deposits of Glenmark, a locality which will ever be celebrated in the scientific annals of New Zealand as the spot which, doubtless, has furnished the largest quantity and variety of bones available for the elucidation of the anatomy of the wonderful, wingless, struthious birds of this country.
The bones described in that paper consisted of a left femur, two ungual phalanges, and a rib, all belonging to the same specimen.
Since the publication of those first notes, further excavations were undertaken in the same locality; and in following down the swampy water-course from which these few remains of Harpagornis were previously obtained a further series of bones was discovered, which, on examination, proved to be another portion of the same skeleton described in that first memoir.
The bones recently obtained were scattered over the bottom of the turbary deposit along the old water-course, 6ft. to 7ft. below the surface, amongst the remains of decaying swampy vegetation. They were mixed up with pieces of drift timber, and with a considerable number of Moa bones, several of them belonging to the larger species (Din. giganteus var. maximus, and Din. robustus).
The bones obtained during these latter excavations consisted of the following:—right and left metatarsus, right and left tibia, right and left fibula, right and left ulna, right and left radius (one fragmentary), right and left scapula, one rib, five phalanges, four ungual phalanges.
[Footnote] * At the request of the author, the publication of this paper at full length has been deferred until all the illustrations can be published of natural size, in quarto form.—Ed.
[Footnote] † Trans. N.Z. Inst., Vol. IV., p. 192.
Our search after the pelvis, sternum, and cranium, was in vain, so that I shall not be able to offer a description of these important parts of the Glenmark skeleton; but, as will be seen in the sequel, I can at least do so as far as the pelvis of the species is concerned, Dr. Hector having kindly handed over to me, for such purpose, a well-preserved specimen of that compound bone, found in one of the Otago caves. *
This list does also not contain any humerus, but we possess at least a fragmentary one, without doubt belonging to this species, which was obtained about a mile above Glenmark, from the banks of the Glenmark Creek. These banks rise in some places about 100ft. above the water-line, in nearly perpendicular cliffs, and consist of postpliocene alluvium, formed by large beds of shingle, with which smaller deposits of sand and turbary deposits are interstratified.
We obtained also the lower portion of a metatarsus, from a similar older postpliocene bed situated close to Glenmark, so that there is sufficient evidence to show that this diurnal raptorial bird existed, like the Dinornis and Palapteryx species, during a long period in New Zealand.
Some time after having made the discovery of the further portion of the skeleton of Harpagornis moorei, in continuing our excavations on the Glenmark property, on the left bank of the Glenmark Creek, and opposite the spot previously alluded to, we obtained, amongst a considerable quantity of Moa bones, a large portion of another skeleton of a raptorial bird, which, although of smaller size than the first-named species, is still of remarkable dimensions. These bones were found not far apart, and near the bottom of the swamp, close to a layer of clay, 7ft. to 8ft. below the surface.
This new find consisted of the following bones: pelvis (fragmentary), right and left metatarsus, right and left tibia, right and left femur, right humerus, right and left ulna, left metacarpal, left scapula, one rib, four phalanges, one ungual phalanx.
In comparing these with the bones of Harpagornis moorei, it became at once evident that they belonged either to a closely allied form, or, making allowance for sex, to the former species.
The disproportion in size of our recent diurnal raptorial birds is so great, that even at the present time the question as to the existence of one or two species of Hieracidea is not yet definitely settled. This remarkable difference in size is also observable in the New Zealand Harrier, where the female is
[Footnote] * This is one of the bones referred to in Trans. N.Z. Inst., Vol. IV., p. 114 (footnote), as having been forwarded by Mr. W. A. Low, which were found in the surface soil under an overhanging rock, and not in a proper cave. This particular bone is in wonderful preservation, and is still covered with periosteum and has the capsular and some other ligaments adherent, while the osseous substance has lost hardly any of the original animal matter which it contained. —J. Hector.
generally much larger than the male bird. Moreover, when comparing the male and female skeletons of Circus with each other, there are some slight sexual differences easily discernible, which might suggest that they belonged to two nearly allied species, did we not know their real relations to each other.
As I shall show further on, the bones of both specimens of Harpagornis belong to adult birds, of which the largest died at a more mature age than the smaller one. Thus the smaller specimen might possibly be the male of H. moorei, assuming the latter to be the female. However, as I am not able to settle this point at present, I shall propose for the second and smaller specimen the specific name of H. assimilis, in order to point out the close relationship of both.
Dr. Hector suggested * to me that the Harpagornis might possibly be the Hokioi of the Maoris, which, however, according to Buller, is the Great Frigate Bird (Fregata aquila), obtained repeatedly in New Zealand, and of which he gives several instances in his work on the birds of New Zealand. †
What the large bird of prey is that I have met several times during my explorations amongst the snow-clad ranges constituting the Southern Alps, without being able to secure a specimen, is a question which I hope future and more fortunate explorers of those regions will one day solve.
Before offering a description of the extremities of Harpagornis, I wish to draw attention to the following table of measurements, in which I have placed in juxtaposition the length of the principal leg and wing bones of all the diurnal birds of prey of which I had material for comparison.
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|Harpagornis moorei.||Harpagornis assimilis.||Aquila audox, Australia.||Circus assimilis, New Zealand.||Hieracidea novæ zealandiæ, New Zealand.|
In comparing, in the first instance, the length of the femur with the
[Footnote] * On the authority of Sir George Grey. Trans. N.Z. Inst., Vol. V., p. 435.—Ed
[Footnote] † Buller's “Birds of New Zealand.” 4to., 1873. P. 340.—Ed.
metatarsus, it will be seen that in Harpagornis the former is longer than the latter limb bone, in this respect resembling Aquila, whereas in Circus the opposite is the case, the metatarsus being longer than the femur. This, to a minor extent, we observe also in Hieracidea. However, when we take the united length of the three principal leg bones into consideration, and compare them with the three principal wing bones, the result is quite different.
Thus, whilst the wing bones of H. assimilis are only 1.52 inches longer than the leg bones (20.88 inches to 22.40 inches) in Aquila, they are, notwithstanding their smaller dimensions, 5.28 inches longer (16.57 inches to 22.03 inches); Harpagornis here again agreeing more with Circus (10.52 inches to 11.34 inches).
According to their different proportions, the wing bones of H. assimilis, when compared with Aquila audax, ought to be 27.53 inches, instead of 22.40 inches their actual size; and, with Circus, 22.50 inches, a result which closely agrees with the above measurement. Of H. moorei we possess only the ulna, the length of which, 10.06 inches, compared with the same bone in the smaller H. assimilis, 9.35 inches, would give for the whole wing bones a total length of 24.10 inches, instead of 29.62 inches, as calculated according to the measurements of Aquila audax.
I wish also to point out that in Hieracidea the united length of the wing bones is actually less than that of the leg bones (7.38 inches to 6.61 inches), although this little bird is remarkably strong on the wing.