NATURE NOTES

Evening Post, Volume CXXIX, Issue 17, 20 January 1940, Page 9

NATURE NOTES

BIRDS IN COOK STRAIT

THE CAPE PIGEON

(By R. H. D. Stidolph.)

One of the prettiest of sea birdi found in New Zealand -waters was seen recently by the writer when crossing Cook Strait. It was the cape -.; pigeon, a bird which enjoys a fairly wide distribution over the waters of the Southern .Hemisphere. One of this attractive species first came into view ; in the vicinity of Tom's Rock, and for. : some time it followed the boat, which was on its way to Picton, flying astern of the ship in ever-varying circles. Not far from the entrance to Tory Channel, Queen Charlotte Sound, two more cape pigeons were seen. The cape pigeon . has from the earliest times been a familiar bird to seafarers in southern oceans, and in consequence is known by several names, including cape petrel, pintado petrel, and spotted petrel. It cannot be confused with any cither sea bird, as its black and white spotted plumage on the back and wings immediately mark it out. In New Zealand seas, particularly those to the south, it is fairly numerous. It is suspected of breeding in the New Zealand area, but its exact haunts have not been satisfactorily determined, although almost without doubt it retires to the Snares, south of Stewart Island, to rear its young. AN "INVISIBLE" BIRDJ Another interesting bird seen-in Cook Strait on the same occasion was the whale bird, or dove petrel, a species that breeds on islands in the Strait. It is a rather small bird, dainty in appearance when seen on','the wing. Alternately, it rises and falls in graceful soars, quickly flapping the wings on the upward movement arid showing the dark upper parts, and the next minute ■■ its white breast. This bird, incidentally, has the plumage of the back and wings a bluish-grey, and so perfectly does this colour tone with the ocean that the bird becomes invisible at a short distance. A case is on record in which a well-known bird . photographer took a photograph of a large flock of whale birds at sea. The air. was full of them when he took the photograph, but when he developed the film not a single whale bird was to be seen; but other species wete'to be seen whose presence tie had not suspected amid the.large numbers of whale birds. This bird is usually seen in large, straggling flocks, every member of which appears to be travelling in the same general direction. The whale bird suffers severely in stormy weather, and at times is to be picked up dead or dying on ocean beaches and occasionally far inlancl. THE GIANT PETREL. As a contrast to the daintiness of the whale bird, the giant petrel,: or nelly, which is nearly always to be. seen in Cook Strait, following in the wake of ships in association with the usual company of black-backed gulls, affords a good example of the great; range in. size of members of the -petrel; family. In size, the giant petrelr compares with that of some of the, smaller, kinds of albatross, and,'moreover,; it-is capable of sustained flight without;even a flicker of movement in its long, narrow wings, in which respect itrgreatly resembles the flight of the albatross. Apart from its powers of flight, which excite general admiration, ?the giant petrel is a rather ungainly rbird, and in its feeding habits is'almost repulsive, as it is more like a. vulture of the seas than anything else.- No food is too foul for it to eat. It is more* often seen in Wellington Harbour than any other petrel, being attracted within the waters of Port; Nicholson by the food readily obtainable there at Ngahaurariga and Petorie, where ilip refuse pipes from the freezing works provide it with a never-failing source of supply. At times, too, it may be seen quite close to the shipping and wharves. It does not appear to* be much afraid of man. Among other places, it breeds at the Chatham Islands, and on islands off Stewart Island. ALBATROSS'S WING-SPAN. The mighty albatross, with. a wingspan of a little over 11 feet, is frequently to be met with in Cook Strait. In fact, at least three species, of albatrosses or mollymawks may be seen in these waters at times, .the-largest of all ocean birds, the wandering, albatross, and its two smaller "relatives, the black-browed and the shy mollymawks. In spite of many statements to the contrary about the ■great width of the expanded wings of the albatross, reports recording a greater width than 12 feet must be regarded with suspicion. According to the testimony v I of American expert investigators about i I lift 6in is the usual width, /vyhile 12ft I would be the, absolute maximum. Men I speaking with forty years' experience • have failed to encounter a single albatross with a wing expanse of over 12ft, * which is five feet less than the width •■ given in some reference books. In any * case, the flight of the albatross arouses the wonder of ocean travellers, and it is quite easy to allow flights of fancy, to account for the extra few feet that , have been added to the actual distance . from wing-tip to wing-tip. The most ■• - interesting development in the bird world in recent years is the successful breeding of the closely-related royal i albatross on Otago Peninsula, the only place on the mainland-of New Zealand where any member of the albatross family is known to breed. All other breeding haunts are ori remote islands. y Is GULL'S INTELLIGENCE. tf Besides other species of petrels, such as the mutton bird, the fleshy-footed shearwater, the fluttering shearwater, > and ttie diving petrel,.all of which may ..■ be seen in Cook Strait, the more familiar black-backed gull is of, special interest, as it has. developed the prao , tice of following the ferry steamer to and from Wellington and Picton. Moreover, not only does this.bird occa- ; „ sionally enjoy a free ride for.part of ; the journey by perching on the der- : '' ricks, but it has also learnt to take C advantage of the air currents caused by,the ship and to keep up with the vessel without any flapping of the wings at all. If this gull is watched it will be seen that immediately it leaves a certain area near~the" stem' of the boat it has to commence flapping * its wings, but when it returns within ; ' this zone it is able once again to follow the ship wtihout any movement of the wings other than a slight adjustment in the plane of flight. It is often a matter of speculation among passengers as to how the gull is able to accompany the. boat with such apparent ease. The reward for the journey across the Strait is to secure any scraps ; er thrown overboard en route. It would : be interesting to know if the samt * birds follow the ship each day -or ' s' whether they differ from day to day.