SHAGS AND TROUT

Press, Volume LXI, Issue 18309, 17 February 1925, Page 8

SHAGS AND TROUT

THE CASE FOR THE SHAG.

(By Edgar F. Stead-.)

At the last meeting of the North Canterbury Acclimatisation Society'a letter was received drawing the Council's attention to the fact that black shags were eating the trout in certain North Canterbury streams. The Council decided, after discussion, that it was of the opinion that shags were not doing any harm to angling in its district. When this was reported in your columns, some correspondents wrote, taking the contrary view. The matter is one thiit'has always interested me, as an angler, and as a lover of birds, and as I have given a good deal of thought to it in the past twenty years, I would like to state the case for the shag as I see it. In 1907 I wrote to the local Society a letter on shags, of which the'following is the major portion:—

• "I would bo the last person to deny •that the. shag does. eat trout,, but 1 am thoroughly convinced that he deserves much more consideration' from anglers than he usually receives. chief point to which I would call your attention is the indiscriminate slaughter of the shags caused by the price that is put . on their heads. .On this account birds are killed which have been bred on the seacoast, have lived in salt water or. estuaries, and have' probably, never even seen a small trout in ail their lives. In many waters where , there are both eels and trout the shags, do a great deal of good by their attacks upon the former. Some years ago T shot nineteen. shags on the Lower Selwyn, and cut each of them open to see what it had' in its stomach. Seventeen had eels, one had some small fresh water crayfish, and one had. a small trout about' seven inches long. Therefore, regarding even-the bird that was eating crayfish as doing damage by taking trout food, the amount of ,good done by the seventeen is out of all proportion to the damage done by the two. "I do not think that the harm'an eel 'can do trout is generally recognised. .Being largely a bottom-feeding fish, it. is an especial menace during the spawn-, ing season. A" 21b eel can eat all the spawn of a 51b trout, and it is just the right fish to find it. Some years ago there was a 71b eel caught in our creek-at "Strowan." It had in its stomaeh one goldfish half digested, and another quite whole,, each of them weighing well over lialf a pound. I-, refer to this as an .indication of the quantity that an eel can eat, for I do not-think it would as easily catch trout as goldfish. But the damage done by eels in trout streams ia not confined to their depredations among _ the ■ trout themselves. Owing to their large appetites they eat large quantities of food that would otherwise serve as food for the trout. This effect of the pres-. ence of eels may be likened to that of rabbits in sheep country. - ' ''The reasons for a shag's preference for eels are many. Weight for weight,: aii eel is more nourishing than a trout,; but a shag can with ease swallow a pound and a half of eel'while it can only manage a one pound trout with difficulty. That larger trout have been taken by shags I am well aware, but as a general rule my remark holds good. The bird's method with an eel is to swallow it head first, getting about four inches v of the fish into its s stomach, the remainder being 'ih his to . some convenient perch, and there, sit throughout the process of digestion, letting the eel slide down gradually as it is digested. ~ I remember once early in the' morning standing below a shag on a poplar branch at the Lower Selwyn, and seeing about'two inches of an eel's tail.protruding from the bird 9bll<I 'The black shag breeds in colonies, usually intrees or on.cliffs overhanging the water, but -often at a considerable distance from its feeding grounds. The young do. not, unless disturbed, leave the'nest until they.are well able to fly,' which is about, six weeks, after they arc'hatched. During this period, they are fed by regurgitation by both parents. At- first this requires no special effort, the old birds delivering a small quantity of wholly digested food to the young. Gradually, however, as the off-, spring grow, and their appetites incre&SQ* the old birds* present the f oou. in a less and less digested condition, at the last, giving it up quite whole. Here is where the eel is most appreciated ove> the trout as. a-form of diet, the greater quantity which can be carried at a time and the marvellous ease With which it can be disgorged,, making'it practically the staple nourishment of the young shags in districts where it can be obtained. Nor.is the presence of dead small tTout m shags nests to. be taken as a refutation of this argument, but rather in support, of it. The old birds always swallow their prey head'-first. ■ Thus • a fish which is too long to be turned inside the bird has to be taken by the young bird tail first and swallowed that way* In the case of an eel, this would make little or no difference, but with a trout it would, more especially if the parent, as it naturally desires to do,' brings large fish .to the nest. The result is ! that the fish, jamming in the young bird's throat, is rejected. "As an example, I would.take the colony of black shags on the cliffs be--1 yond Lake Forsyth. These birds largely use as their feeding ground Lakes Forsyth and Ellesmere. Arriving on i-the lake at the- earliest streak ! of dawn, they immediately begin td fish in the shallows at the mouths of the 'streams that flow into it, or in comparatively shallow water along its shores. Eels, common as they are throughout the whole lake, absolutely swarm in these particular places, and the relative number of eels to trout taken in these localities would be, I should think, at least 50 to 1. "In a. colony of shags on the Rakaia River, the old birds of which I several times patched fishing during their breeding season, I only saw two trout caught out of a total catch of about twelve fish; the remainder being eels. This was readily- to be observed as the shag, being unable to swallow its prey under -the water, has to bring it first to the surface. • ■■ - " And iiow. I come to the actual taking of'trout by shags. As I have already said, in districts where there are eels the number jtf trout taken is smaller than-is usually imagined; and there are very few streams in the South Island where eels are not plentiful. I remember well, late in April, 1901, the "Waimakariri being perfectly ~ clear, I saw numbers of- eels of- all sizes working their way. up stream under both White's Bridge and the bridge over the cutting. In October, 1903, the was crystal clear, and I saw the same thing at the Railway Bridge. At the same time there are, I believe, many streams in. the -North Island which are almost, if not entirely, devoid of eels. Yet even there I claim that the shag is not an unmitigated evil. "Most of you will, i I think, agree* with me that the danger with many of our streams and rivers" is not of their depletion of trout but of over-stocking. Most of us, also, are'well aware of the degeneration, that takes places, in any race , thathas no natural enemies—where, that is to say,, i there is no agent that will bring about the survival of the fittest. • In the eaee of trout an eel . can be of * .

little use as such an agent, since by eating the ova it destroys the trout- before the latter has an opportunity of showing its fitness or otherwise. A shag, on the other hand, taking trout of anything from five to 14 inches long, is almost certain to get the weaker members of_ a shoal first, the stronger escaping bv their superior agility and Bdimming powers. I suppose that of flhe trout in the Avon, .10 per cent, are miserable, long, thin iish weighing anything up to lilb. I think you would have.great difficulty iu finding, any such percentage in a stream where there are shags' fishing, and it is my opinion tliat a few shags fishing in the Avon.would soon reduee the percentage there. The Upper Selwyn is enormously overstocked considering the size of the stream and the quantity of tibc food supply. The result ,is that the average size of the fish is nothing like what it was years ago, nor are they iii such good condition.

"I have heard that there is a marked deterioration both in size and condition of the fisli iu Lake Rotorua, winch is generally ascribed to over-stocking. "Once when staying with Mr George Rhodes, at Meadowbank, I got up early and started down the Selwyn before daybreak. When it was just dawn I saw nine shags settle .in a. long pool and commence fishing. Within a few minutes; two more pairs of birds arrived, making thirteen in all. I put down my rod and basket, and, creeping to the edge of the pool, I peered through the grass on the bank. The birds were all at the top end of the pool, diving in every direction. As I watched they came down stream towards me, quartering the pool very carefully. It was a most- interesting sight, for they passed within a few yards of me; some diving, some swimming with their head and neck under' water. . I could clearly see their bright-, beaming green eyes as they came up, gasping, and follow their glistening bodies as they darted hither and thither under the surface. Down to the tail end of the pool they worked and here at last one of them caught a fish, to be immediately set upon by.. several of the others who, grunting and gurgling, tried unsuccessfully to rob liimt of his prey. I fancy it was a trout, though I did not see it clearly. Then one of the birds saw me and the whole flock rose and flew off up stream. Three hours later on my return journey past the pool I counted the waves of eight or ten small trout as they rushed from tilie shallows into the deeper water. This, I think, shows that a shag does not readily catch a healthy trout, but at the same time I feel sure that any eels or sickly trout in that pool would have been caught. "And now I will come to the question from a purely aesthetic point.of view. With many fishermen the jov derived from a day's fishing is not to be gauged alone by the bag they , bring home, but also by the number of interesting' natural incidents which they meet with during their tramp. The presence of bird life along a stream lends fishing a delightful charm for the angler, particularly if he is not getting over-good sport. The little doterel, running swiftly, among the stones, pausing every now and then to give-its staccato call "pit pit"; the fantail, performing all manner of. aerial evolutions over the surface of the water while procuring its - insectlunch; the long-legged stilt trying, by means of very realistic acting, to luie ■us away from its nest or its young ones, > secreted at the ■ water's > edge; the duck, embodiment of maternal anxiety, leading her mottled brood acrosssome dark, willow-fringed pool—surely these things cannot fail .to attract the attention and help to moke -for the day's pleasure. . And even the old shag, though possessed perhaps of no great ethereal beauty, is yet a very interesting''featu'rfe of the ;' landscape 'as'he sits on some log or bough with wings outspread drying 'in the sun, or rises from. the water at .our - approach with his "body inclined' at an angle, his whole appearance being much that of some fantastic creation; on a Japanese screen.- And .year by' year our bird 'life is decreasing. Decreasing to rapidly, indeed, that before long much of it will have entirely disappeared, so that it behoves us to protect what of it we can while we may. "During ' the last few years this Society has'paid quite a, considerable sum on' shag heaas, a large number of which have, I believe, come from the Ellesmere district. The ideal condition would be for the shags to ber protected and a permit granted each Acclimatisation Society for its authorised rangers to- shoot .them in districts where mature consideration showed that they were really inimical to the interests of the angler; but at the very least the price should be taken off their heads—a price that makes 1 them sought after by eivery Tom, Dick and Harry, who know nothing of the merits of the case and who care less, while ' probably their only method of trout-fishing is one, involving the use of a stable lantern and a. pitchfork." In the eighteen years since the letter was written, I have fished throughout New Zealand and have much more evidence on the subject, all of which tends to confirm the views I then held. These views will be given in my second article. (To be Concluded.)