Vol. 1 DECEMBER 31, 1961 No.6

The Nesting of the Pacific By HAROLD E. TARR, Nunawading, Victoria.

The Pacific Gull ( pacificus) makes a perfect picture in black and white with a snow white head and under surface, black back and wings, white tail with a broad black subterminal band and yellow legs and feet. The formidable beak is orange with a reddish tip, while a conspicuous whitish iris shows beneath an orange eyelid. This adult plumage is not acquired until the fourth season. Both sexes are alike in plumage. With a total length of 25 inches and having a wingspan of about 5 feet this weighs approximately 2):1: lbs. The normal flight is performed in a heavy cumbersome manner beating the wings at the rate of 75 times to the minute. They are complete aerial artists, however, in violent weather, using air currents to glide acout effortlessly in great circles back and forth over the same ground. They will change course without even a flap of the wings. The Pacific Gull is chiefly found in the southern Australian seas. They stay about the bays and estuaries on the eastern side of the Continent but are mainly coastal on the western side. Although fully plumaged rarely appear in large numbers, the immature birds will often flock after the breeding season. The range of this bird extends to Onslow on the Western Australian coast but, although published records give the range as far north as Rock­ hampton, Queensland, on the eastern side, I have never observed this Gull farther north than Harbour, N .S.W. There are many inland records of these birds being observed on fresh water lakes, but I have never seen them more than a mile from the coast and then only during violent weather. T he main food appears to be fish and marine but they also take eggs and young of other nesting sea-birds. They will carry shellfish, such as mussles, and drop them on to rocks from a height in order to break them open, and will often use a particular reef or rock as a breaking platform. Sometimes they appear to play with shells. A Gull will fly with an empty shell in its beak and suddenly drop it, only to swoop down and retrieve it before it reaches the ground . I have observed birds trampling the sand and pebbles in order to disturb some type of food, and there are published accounts of birds feeding on freshly ploughed land, in the company of Silver . General feeding habits resemble the 148 TARR, Pacific Gull [ Bird Watcher

Silver Gull as far as gathering food from beaches and following ships to gather waste food thrown overboard. Breeding activities seem to be confined to a common resting place near which the nest is later constructed. The pair will spend much time in this area and coition will often take place there. When the eggs have been laid one bird. probably the male, remains at this vantage place and from here will attack any other Pacific Gull intruding in its territory. The intruder will approach with its neck arched in a stiff attitude, much in the manner adopted by the , and then commence picking up pieces of grass or sticks and dropping them; at other times throwing them over its back. These actions seldom finish in a fight as the aggressor usually departs before the advances of the resident bird. Nests are mainly constructed on elevated positions and are often placed amongst mesembryanthemum. Sometimes two pairs of the large Gulls will build their nests only 50 yards apart but, provided territorial rights are respected, they will remain on friendly terms. Breeding has been observed on islands off the Western Australian coast and on the headlands and islands of Tasmania. The nests are compactly made of sticks, flower stalks and grasses and lined in the bottom with finer materials. The nesting chamber is 9 inches in diameter and usually about 3 inches in depth and the egg-clutches vary in number from one to three. The eggs are olive-brown in colour with blotches of brown and grey. An average measurement of twelve clutches was 74 mm. x 52 mm. The breeding season ranges from October to January. Incubation nearly always starts before the egg-clutch is complete and both sexes share in the duties of incubation. The eggs are usually laid at intervals of two days and hatch within 26 to 28 days. The nestlings are wonderful examples of camouflage as they blend perfectly with their surroundings. They will sometimes disgorge food if suddenly disturbed. The head of the nestling is coloured creamy buff with brownish spots, upper parts greyish buff faintly spotted with brown, under pale greyish buff. The feet are a dark lead colour and the basal portion of the bill green. The young birds are very active and for the first week appear to be fed mainly by one parent on partly digested food. I presume this parent to be the female as its bill is always slightly duller than the bill of its mate. When the bird is ready to fly at the age of eight weeks it is evenly coloured with a dark brown plumage, which it retains during the first year, and has a blackish bill and brown feet. In this and subsequent brownish phases they are often miscalled Mollymawks and Nellies by fishermen and coastal dwellers. The former name actually belongs to our smaller Albatrosses and the latter to the Giant Petrel. In the second year, the birds have a rather mottled brown and white plumage and the bill is now a greyish colour. In the third year they are much like the adult in colour but have many flecks of brown on the head and other parts and a bill of brownish yellow. During the fourth year full adult plumage is attained. December] TARR, Pacific Gull 149 1961

Nest and Eggs of the Pacific Gull. Plate 32.

Pacific Gull Nestling showing camouflage. Plate 33. Photos by Harold E. Tarr 150 T ARR, Pacific Gull [ Bird Watcher

The normal call of the Pacific Gull is a harsh drawn out note, but sometimes a short sharp note will be uttered. In the nesting season the call resembles a high pitched human voice calling "Ho­ bo". The first time I heard this note I was alone on an island and I was quite sure it was human voice calling. The only bird the adult Pacific Gull can be mistaken for in is the Southern Black-backed or (Larus domi­ nicanus). The Kelp Gull however, is a shade smaller and lacks the black subterminal band on the tail. For a person who has lived among Pacific Gull s practically all his life the slightly different bird immediately attracts attention. My first Australian observation of thi s bird was at Middle Park Beach, Victor:a, on January 26, 1956.

Some Notes From Noosa Heads, Queensland By H. H . PEDDIE, Maryborough, Queensland

During a recent visit to the Noosa Heads area the Noisy Pitta (Pitta versicolor) and the Regent Bower-bird (Sericulus chrysoce­ phalus) were observed in the National Park. These two were not recorded at the 1958 Royal Australasian Ornithologists Union's Camp-out at Noosa, although the Forestry Ranger, Mr. Harry Woodley, stated at the time that he had often heard the Pitta calling in the Palm Grove area of the Park. However, in 1958 and during another visit in 1959 I did not hear or see the Pitta at Noosa, although three birds were heard and seen in the Kondalilla National Park, near Montville in the Blackall Range, during a brief visit in 1958 while attending the Camp-out. A bird was heard calling several times this year ( 1961) in the Noosa Heads Park between half past five and six o'clock in the evening, and at 6.05 a.m. on September 24 a bird, believed to be a male, was seen hopping into the undergrowth just inside the Tangle­ wood track. At the time I was with Mrs. Essie Green, of Noosa Heads, and we were both able to identify the bird, although at first we had thought that the rustling and scraping was caused by a Grey or Rufous Thrush. However, the typical hopping gait of the Pitta makes an unmistakable sound which became quite familiar on subsequent days. The Park was in the grip of a prolonged dry period and the thick carpet of leaves on the tracks and forest floor made it easy to pick up sounds. Thanks to the work of the Ranger, the tracks were swept clear of leaves and this made movement along the tracks almost noiseless and the observation of birds much easier. On the morning of September 25 , at 6.35 a.m., I was waiting in the area where we had seen the Pitta the previous day, and had been concealed under the dry foliage of a fallen tree for about half an hour, when I heard the familiar hopping sound of an approach­ ing Pitta. The bird roughly followed the course of the previous Decembec J TARR, Pacific Gull 151 Jol6 l

T he brooding Gu ll showin g the heavy bill with the red marking on the end. Plate 34 .

Pacific Gull In second year plumage. Pl ate 35. Photos by Harold E. Tarr