NEW ZEALAND SHAGS

Grey River Argus, 11 September 1939, Page 5

NEW ZEALAND SHAGS

MANY SPECIES PROTECTED. [By R. H. D. Stidolph.l Probably more is heard about the shag in New Zealand than any other bird and perhaps few people are aware that there are thirteen different kinds of shags in this country and its outlying islands, and that the great majority are protected species (writes R. H. D. Stidolph in the “Post”). Although this group of birds is well represented in species or sub-species, the numbers are not as great as may be supposed. There is no greater fallacy than a belief that may be prevalent that all shags are destructive to trout. This is far from being the case; in fact, out of the thirteen kinds found in New Zealand waters, only one is to be considered as having any influence on the propagation of trout, the well-known and widely-spread black shag. It occurs in all parts of the country, and although everywhere persecuted, rightly or wrongly, it appears to be able to hold its own. No one denies that it catches trout, but there is evidence that indicates that it is blamed for a state of affairs in which it is quite innocent and the really potent factors in the diminution of trout in our streams are overlooked—such as the effects of deforestation on water catchment areas and consequent erosion. Rivers which carry severe floods in winter and almost dry up in the summer are not likely to provide conditions for the increase of trout.

Another large shag, about .the same size as the black species, is fairly widely distributed, though it is much more a coastal bird than an inhabitant of inland localities. It is the pied shag, so named because its plumage is black above and white below. There is no need to confuse it with any other species, as its white undersurface is most conspicuous. It cannot be accused of destroying manytrout, as by habit it is mainly a seafeeding bird, though occasionally it may be seen on rivers and lakes near the coast. On the whole, the pied shag does little harm, and in coastal areas, such as in the Marlborough Sounds there is no reason at all for the ruthless destruction of this bird that is the delight of visiting yachting and launch parties in that region. A more familiar bird to many people is the so-called white-throated shag, which is fairly numerous in many parts of New Zealand. It is found on the coast and also in inland districts. Although there is little or no evidence that this bird takes trout, it is much persecuted, and it would not be surprising, if a scientific investigation were made into the feeding habits of this small shag, that it would be found to be more beneficial than otherwise in its relation to trout fishing interests. Control of wild life in New Zealand is so haphazard that it is possible for a bird to be condemned on totally inadequate evidence.

The white-throated shag is a very variable bird. Some birds have the normal plumage—a white area on the throat and sides of the face—while others have the whole of the undersurface white, muefi the same as the pied shag. The exact relationship of these two forms and the many intermediate phases is not so properly understood. In any case, the birds appear to belong to one variable species and all have similar habits to those of the typical shag. The only other shag found in inland mainland areas in New Zealand is the little black shag, a small edition of the large common bird. So far, it has been recorded only from the Auckland district.- For many years it was known to occur in the Bay of Islands, and it was only recently that it was found to be well established also in the Waikato district. All the same, on account of its restricted distribution, it is not a very well known bird. Its entirely black plumage and small size distinguish it from other species, though it must not be confused with the young white-throated shag, which, until it assumes the adult plumage, has little or no white on the throat. Again, there is no evidence that the little black shag feeds on trout; its economic position in this country has never been investigated. In spite of that, there are many people who are ready to shoot the bird on sight.

PURELY COASTAL BIRDS. Besides these birds which occur inland as well as on the coast, there are others that are confined to coastal waters. These later birds, the purely coastal shags, are all protected species. Among the most handsome birds in this category is the beautiful spotted shag, which occurs sparingly in certain localities in both islands, while a near relative, known as the blue shag, is restricted to Stewart Island and the neighbouring coast of Otago. Neithei’ the spotted nor the blue shag can conflict in any way with the interests of freshwater anglers, so that trout fishermen can have no misgivings on that account. Although they now are totally protected, these birds have been sadly decimated in numbers, specially the spotted shag in the Hauraki Gulf, where it has become extinct in many of its old haunts. In the breeding season it is ornamented with two crests on the head. Otherwise it may be distinguished by its brownish grey back and wings, which area is fairly liberally marked with black spots. There is also a white stripe down the side of the neck. Another shag in the same group occurs at the Chatham Islands, closely resembling the mainland bird. This bird is likewise totally protected. < It is to be hoped that all will increase again in numbers, though there appears to be no efficient system in force to ensure that the remaining colonies are not molested by vandals.

SOUNDS POSSESSION. Besides the spotted shag and its relatives, there is another group of purely coastal frequenting shag which likewise are protected species. There are seven or eight forms in this group, all of them being particularly handsome birds. ■ Most, if not all, carry a crest on the head, and in general coloration practically all have black heads and upper parts, relieved with a conspicuous white area on the lower back and white underparts. Of the eight forms, three occur on the mainland coast of the South Island, but only in restricted areas. The Marlborough Sounds boasts possession of the so-called rough-faced or carunculated shag, which is not known to occur elsewhere. Such an interest-

ing and beautiful bird is worthy of all the protection that can be extended to it, and in view of its restricted distribution and its small numbers, it is essential that the bird be effectively protected. Although it has its nests on an almost inaccessible rock, it nas been subjected to much persecution in the past. The Chatham Islands have a near relative and another closely-related bird is found on the coast of Stewart Island and of Otago. In the same locality, a somewhat similar bird but with the plumage entirely black, is also found and interbreeds with the white-breasted bird. Other forms of this group inhabit the s:ubAntarctic islands,