THE SHAG.

Press, Volume LXVI, Issue 20097, 28 November 1930, Page 12

THE SHAG.

A MENACE TO TROUT. OTAGO INVESTIGATIONS. [THB FBZBS Special Berrl««.] DUNEDIN, November 27. As a resnlt of the publication some time ago of a letter in the Press, in which the writer stated that he was yet to be convinced that shags ate trout, the Otago Acclimatisation Society arranged for some Shags to be sent to the Otago University, in order that an examination of their stomach contents might be made. The following is the report of Mr A. D. G. Blanc, who made the investigations: I have investigated the stomach contents of the final lot of shags sent me. Of the four sent two were empty, and the other two were full of fith of varying sizes'up to six inches in length. In those cases where identification of the fish was possible, I found that all the fish were trout. Altogether I have examined 25 to 30 stomachs. From a scientific point of view this number is too small to permit of drawing definite conclusions, but I consider that the results found are a fair index to the diet of the bird. The following is a summary of the results obtained— One eel only was found. 2. Five out of every six stomachs were full of fish Contents. ' 3. Of the remainder all were empty, with the exception of the one containing the eel. 4. Where identification was possible the fish proved to be trout. 5. In practically all cases the fish were from 3in to 6in in length. As pointed out, I consider these results are a fair index to the diet of the bird in that locality from which the birds were obtained. I am well aware of the fact that there are some investigators who have yet to be convinced that the shag is a menace to trout. For my part I believe that the shag's diet is almost wholly composed of fish and the type of fish eaten is the type of fish which is most abundant in the particular locality. Another Indictment. Mr W. W. Mackie, of Tapanui, writes as follows to the secretary of the Acclimatisation Society:— From my boyhood days for the last 50 years, I have shot the black shag on the Pomahaka and have opened scores of them, finding in almost every case from one to two fish, varying in size from six inches in length up to Jib or even lib in weight. On very few occasions have I found eels in them, and these were generally tho small eel called kuni kuni by the Maoris, which have suckers instead of mouths, and stick to the rocks. Tho writers of the articles in the Press in defence of the shag were simply theorising, and have never observed the shag at work. I have frequently watched them fishing and have seen a single shag swallow two trout, about Jib weight, within a quarter of an hour. At a conservative estimate I have come to the conclusion that each shag accounts for three trout per day on an average all the year round, and my conclusion is based on direct observation o£. their habits throughout a period of 50 years.