Skua
2 of the 6 encyclopedias on this shelf carry an entry for Skua. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
in ornithology, the popular name of any species of the genus Stercorarius. They are predatory swimming birds, rarely fishing for themselves, and generally pursuing smaller gulls and terns, and compelling them to drop or disgorge their prey. Four species visit the temperate regions of Europe and America: S. catarrhactes, the great skua, which breeds in the Shetland Islands; it is about 24 inches long, and of somber plumage; S. pomatorhinus, the pomatorhine skua, 21 inches, dark mottled above, under surface brown (nearly white in old birds); S. crepidatus, the Arctic or Richardson's skua, about 20 inches long, occurring under two different plumages, one entirely sooty, the other with white under parts, and S. parasiticus, the longtailed or Buffon's skua, about 14 inches long, upper part of head black, upper surface brownish-gray, under surface white. SKULL. The skull is divided into two parts, the cranium and the face. In human anatomy it is customary to describe the former as consisting of eight and the latter 14 bones; the eight cranial bones, which constitute the brain case, being the occipital, two p parietal, frontal, two temporal sphenoid and ethmoid; ethmoi while EUROPEAN SKULL the 14 facial bones, which surround the cavities of the mouth and nose and complete the orbits or cavities for the eyes, are the two nasal, two superior maxillary, two lachrymal, two malar, two palate, two inferior turbinated, vomer, and inferior maxillary. The bones of the ear, the teeth, and the Wormian bones are not included in this enumeration. The lower jaw articulates with the temporal bones by means of a diarthrodia joint, but all the others are joined by sutures. On the base of the cranium the occipital and sphenoid bones articulate by means of a plate of cartilage (synchondrosis) in young subjects; in adults this becomes bony union. Sutures are named from the bones between which they are found, but to those around the parietal bones special names are givene. g., interparietal or sagittal; occipitoparietal or lambdoid; fronto-parietal or coronal; parieto-temporal or squamous. During adult life many of the sutures close by bony union and disappear, but a 6 e d h C I HUMAN SKULL f-Malar bone a-Frontal bone g-Nasal bone b-Parietal bone h-Upper jaw bone c-Occipital bone i-Lower jaw bone d-Temporal bone e-Sphenoid bone both the age at which this occurs and the order of its occurrence are subject to variation. Wormian bones are irregular ossifications found in relation to the sutures of cranial bones, but these bones are seldom seen in relation to the bones of the face. The fact that concussion of the brain scarcely ever proves fatal, unless there NEGRO SKULL is also fracture of the skull, affords the most distinct evidence that the skull is constructed in such a manner that so long as it maintains its integrity it is able to protect its contents from serious lesion. There are two points in the architecture of the bones of the face which deserve special notice-viz. (1) the great strength of the nasal arch; and (2) the immobility of the upper jaw, which is xed by three buttresses the nasal, the zygomatic, and the pterygoid.
Aiton's Encyclopedia (1910)
an Arctic gull. The word is Norwegian, allied possibly to scout. The common or great skua attains the length of two feet. Its general color is a blackish brown, variegated with chestnut and white sports. This gull is abundant in Arctic regions . It nests on the rocky shores and lives on a fish diet.
What Has Changed in the Last Century
The birds Collier's listed in 1921 under Stercorarius are still recognised, but the names have been shuffled: what Collier's called S. parasiticus, the long-tailed skua, is now Stercorarius longicaudus, while parasiticus is the Arctic skua, known in North America as the parasitic jaeger. Skuas are now placed in their own family, Stercorariidae, and DNA work has confirmed their closest relatives are the auks rather than the gulls Aiton's called them in 1910; the great skua, long split off as Catharacta, has been returned to Stercorarius by most authorities, and southern-hemisphere species such as the south polar skua fill out the group. Aiton's line that the bird "lives on a fish diet" understates it — great skuas kill other seabirds outright and scavenge heavily from trawler discards, and Collier's kleptoparasitic chases are only part of the story. The Shetland breeding colonies Collier's mentions remain the species' world stronghold, but the H5N1 avian influenza outbreak that reached Scottish seabird colonies from 2021 killed great skuas in very large numbers there.
Written for this edition, 2026.