128 SMITH, The White-winged Black Tern [ Bird Watcher The White-Winged Black Tern in Southern Victoria By F. T. H. SMITH, Kew, Victoria SUMMARY The White-winged Black Tern is recorded from mid-southern Victoria for the first time. An isolated occurrence on January 5, 1963, and several birds between December 17, 1963 and August 23, 1964, with a peak of 22 birds at Cherry's Swamp, Altona, on March 21, 1964. Although several birds had started to change to breeding plumage only one remained long enough to attain the complete nuptial dress. The species is compared with the Whiskered Tern, with which it freely associated, and the Fairy Tern. Notes are given on plumage changes, flight, feeding action, food, calls, display and aggressiveness.

The White-winged Black Tern (Chlidonias leucoptera) some­ times occurs in large numbers in northern Australia when it is on migration, but it is rarely recorded in the southern parts. The species has visited the south-west of Western Australia, and has now been recorded in South Australia. From Tasmania, there is a specimen which was shot at Rushy Lagoon on March 3, 1962, after being first observed in the vicinity on December 16, 1961 (Wall, The Emu, 62 : 265-266.) The first Victorian sight record was obtained on December 29, 1958, by four observers, near Mystic Park in northern Victoria, when a bird in non-breeding plumage was seen at Lake Tutchewop, and on the following day at Lake Kangaroo (Bourke and Lowe, The Emu, 60 : 65-66). At the Butts Pond, Port Melbourne, on January 5, 1963, there was a small tern, somewhat like a Marsh Tern, perched on floating rubbish well out from the bank. It was examined as thoroughly as was possible under the circumstances, with 10 x binoculars. The bird was largely white on the under parts and about the head, with the upper-wings, back and tail greyish. A black area on the crown extended down behind the eyes, leaving a strip of white between the eye and the black marking. This bird, from later experience, was undoubtedly a White-winged Black Tern in non­ breeding plumage. On December 17, 1963, just over eleven months later, at the same pond, there was another small tern similar in all respects to the bird that was seen in January. It was feeding over a stretch of deep water at the north-east corner of the pond in a manner that was typical of the Marsh Tern- fluttering over and dipping down to regularly pick from the surface of the water. Having watched the Whiskered or Marsh Tern (C. hybrida) many times in the field, I was able to satisfy myself that this small tern was not only marked differently to a Whiskered Tern in the non-breeding plumage, but it also had a somewhat different feeding action and flight pattern. June ] SMITH, The White-winged Black Tern 129 1965

On the following day I watched the bird for about two hours, with 15 x binoculars mounted on a tripod, and was able to check the plumage details closely and the method of feeding. Although the flight and feeding actions were essentially similar to those of the Marsh Tern, there were minor differences between the two species. Generally the feeding flight of the White-winged Black Tern was more fluttery and more buoyant and graceful than that of hybrida, and the dips to the water were made from a lower level and in a more regular pattern across the surface of the pond. This particular Tern, and later others that I observed, would select a stretch of water of perhaps a hundred yards in extent, and flying against the wind, if present, at about two feet above the surface would, every few feet, flutter for a second or two, then drop down and pick quickly from the water until the course was covered. Then rising higher, rapidly, it would fly directly back to the starting point to begin all over again . . The one stretch would be worked for several minutes, then another would be selected, and another, until nearly all of the pond surface had been methodically covered. The Port Melbourne bird, and those observed later, never broke the surface of the water with its body whilst feeding, but Whiskered Terns were observed to do this frequently when "plunge-diving" from a greater height. The bill of leucoptera rarely went any depth into the water, and the tiny items of food seemed to be taken cleanly from the surface. The Butts Pond bird was not seen after December 18, but, while watching a large number of Whiskered Terns at Cherry's Swamp, Altona, on December 27, I noticed five more White-winged Black Terns among them. From then on their numbers gradually increased till there was a peak of 22 at that swamp on March 21 , 1964. After that date their numbers began to dwindle as the urge to return to the northern breeding haunts developed. The last bird to be seen at Cherry's Swamp, was noted on June 21 , 1964, and, on the same day, another bird was noted at the Dairyfarm Swamp, about a mile further west. During the occurrence of this species in the Melbourne area some more Terns were seen at the Werribee Sewerage Farm, several miles further to the south-west. The first White-winged Black Terns to be seen at the sewerage farm were noticed on January 12, 1964, when two birds were observed. The last record was of a single bird, in full eclipse plumaget on August 23, 1964. Most of the leucoptera seen over the period from December 17, 1963, to August 23, 1964, remained in the full non-breeding plumage, or changed very slightly, but some birds did make a marked change to breeding plumage. THE CHANGE TO BREEDING PLUMAGE Cherry's Swamp at Altona was frequently visited by myself, and other observers, to watch the activities of this species and, in particular, to watch for signs of the change to nuptial garb. 130 SMITH, The White-winged Black Tern [ Bird W atcher

The change became apparent about the end of December when I noticed that the black on the crown was extending down the nape. Toward the end of January some birds showed an obvious paling of the upper wing-coverts. On February 2, 1964, one bird was outstanding in its plumage pattern. It showed fairly large black patches on the throat, breast, abdomen and flanks, and the back of the neck near the mantle. The effect of the black blotching against the white body resembled the markings of a Dalmatian dog. Also, in this bird, the under wing-linings showed dark mottling. Two or three other birds, on the same day, showed some minute dark speckling of the under parts and some patchy darkening of the under wing-linings. All the bills were dark, and the legs and the feet were reddish. From February 2, breeding plumage changes were noticed on a few birds, but most remained in complete non-breeding garb. As some birds became heavily marked they disappeared from the area and, no doubt, were on the move north. The blacker the body and the under wing-linings became the whiter the upper wing-coverts and tails appeared. Only one bird that began the change to nuptial dress at Cherry's Swamp remained there until it had fully changed. This bird was observed closely as the black of the body, head, neck and back gradually merged on to the white areas, until no white speckling was left and the black was evenly distributed. It had attained full breeding plumage by April 19, and it remained at the swamp until May 3, but it could not be found there on or after May 9, 1964. This particular White-winged Black Tern, when in complete nuptial dress, was a glossy black over the entire head, neck, the whole of the body to the lower abdomen, back and under wing-linings. The upper wing-coverts, upper and under tail-coverts, lower back and tail were pure white. I found it difficult to detect any red on the mandibles even at close range. The bill generally appeared dark, but once or twice in brilliant sunlight I noticed a subdued reddish tinge near the gape. The legs and feet, however, were very red. CALL-NOTES The White-winged Black Terns were remarkably quiet during the first few weeks of their stay, although it was on December 28, 1963, that I heard the first calls. These were emitted in anger, or perhaps alarm, when the birds were pursued by Whiskered Terns for food that they had caught, or when they were defending their perching sites. The notes resembled a high pitched "Kreek­ kreek" and were unlike those of C. hybrida On February 29, 1964, at Cherry's Swamp, I found that they were becoming more vocal, and there was much noisy chasing of each other. Whilst in pursuit they gave voice to loud insistent, but thin, notes which sounded like "Keeek-keeek-keeek", with the accent on the beginning and end of each "Keeek". June ] SMITH, The White-winged Black Tern 131 1965

When about to alight, usually on a small rock in the water, a sharp "Krip-krip" was uttered, and it seemed to serve as a warning to other birds perched in the vicinity that a landing was under way. When I was endeavouring to conceal myself, under some small lignum bushes, for closer observation of the species, some of them saw me, and soon several birds were fluttering low over my head. Their warning notes and cries of anxiety to my ear resembled "Kreea-kik-kik", with sometimes an extra one or two "Kik" notes added. Toward the end of March they were becoming even more vocal than the Whiskered Terns with which they were associating, and quite often a bird on the shore and one just alighting would call together, a loud "Kreeetch-kreeetch" and similar cries. On April 26, the nuptial-plumaged bird was feeding back and forth over a small section of the swamp near the shore. It was later joined by a few eclipse-plumaged birds of the same species but, apparently desiring to retain the sole right to its chosen feeding place, it spent much time chasing the others away. While so engaged it gave vent to several calls of annoyance which, when put to paper, were a rapid "Kik-kik-kik", etc. Occasionally there was a single sharp "Kik". This series of notes was harsher at times, and then it was more like "Kek-kek-kek", or a single "Kek". Another variation of the annoyance call was "Chik-a-tik-tik", and also "Krrek-krrek-krrek". When a long distance chase was under way the notes were mainly loud "Kreeks", or a long drawn-out, more attractive, thin "Krrreeeeek", with a rising inflection. Sometimes, as the birds flew about the swamp feeding, the calls were "Kreeetch" and "Kreee-itch", which could be heard from some distance away. GENERAL OBSERVATIONS While the White-winged Black Terns were at Cherry's Swamp and the Werribee Sewerage Farm, they associated freely with the Whiskered Terns. This was a fortunate situation for those observers who wished to see these two closely related species together. In the air both species appeared to be about the same size, but when at rest, side by side, the discrepancy in the bulk of leucoptera became markedly apparent. The White-winged Black Tern appeared diminutive when next to the Whiskered Tern. Although it had a less upright stance it was obviously slimmer in the body, and thinner and shorter in the legs, and it had a shorter, finer bill than hybrida. Once, at the Werribee Sewerage Farm, I saw three species of small terns squatting side by side on a gravel roadway. They were the Whiskered Tern, White-winged Black Tern and Fairy Tern (Sterna nereis). The smaller size and short slim legs of the White-winged Black Tern were noticeable against the more robust Whiskered Tern, but the Fairy Tern was the smallest, being a little shorter and slightly more slender than leucoptera. 132 SMITH, The White-winged Black Tern [ Bird Watcher

On a few occasions at Cherry's Swamp I saw a display that may have been a greeting ceremony. This activity usually took place on the flat shore near the water, and I quote from my notes of March 27, 1964, a ceremony that I was able to view from close range. "It (the ceremony) usually happened just after one bird had alighted (but not always after alighting; sometimes it oc­ curred spontaneously on the shore) near others, when the recently arrived bird and the one nearest to it, Oli even three or four together, would stand as erect as possible on their short, spindly legs, with necks extended upwards, and bills pointing almost vertically, they would face each other for a few seconds, or a minute or two, until one bird relaxed. The others would then relax also. It gave me the impression that each bird was trying to appear taller than the other." This display was usually silent, and while it was in progress the little tableau that they formed reminded me of pictures I had seen of the greeting rites of some species of penguin. Despite its smallness the White-winged Black Tern was not lacking in courage or aggressiveness. Several times I witnessed attacks by this species on much larger birds, particularly Silver Gulls (Larus novae­ hollandiae). The Gulls would stand in groups, at rest, on the flat shore of Cherry's Swamp, keeping roughly about two feet back from the edge of the water. The Terns often roosted on the strip of ground between the Gulls and the water. Sometimes the Gulls would crowd onto the Tern-strip and, when this hap­ pened, they were usually met with a barrage of savage pecking from the smaller birds. Once I saw a White-winged Black Tern waddle a few feet up to a Silver Gull to force it from its position. It jumped up and pecked it until the larger bird retreated and the small aggressor was left squatting in its place. On other occasions I have watched, for several minutes, Silver Gulls chasing a single leucoptera out over the swamp. Although the bird being pursued would screech loudly, it always outflew its pursuers easily with a series of rapid manoeuvres which made the Gulls look like they were novices at aerobatics. A Swamp Harrier (Circus approximans) passed low over the swamp one day causing alarm among several shore frequenting birds, and it was immediately set upon by several Spur-winged Plovers (Lobibyx novae-hollandiae), and a single leucoptera, which made two determined dives at the Harrier before returning to the swamp-edge. Although I saw White-winged Black Terns make many hundreds of feeding swoops during the months they were near Melbourne, I was not able to specifically identify any of the very small food items that were taken. The bird that reached complete breeding plumage was seen to take a number of small beetles from algae floating in the water. At the Werribee Sewerage Farm on January 18, 1964, a hot humid day, there were myriads of flying insects rising in swirling, June ] SMITH, The White-winged Black Tern 133 1965

towering columns all about the area. Two White-winged Black Terns were noted flying into the living columns, several feet above the ground, to obtain the insects. 1964-1965 SUMMER On November 8, 1964, a single White-winged Black Tern, in eclipse-plumage, was noted near Point Cook. It flew along the shore of the bay, and later entered the Altona Saltworks area. At the Werribee Sewerage Farm, on November 21, 1964, there was a single bird in non-breeding plumage. It was associating with a large gathering of small migratory waders. As the waders flew about en masse, when they were disturbed, the Tern was caught up with them and managed, quite capably, to emulate the flock discipline of the rapidly moving birds, as they sped about the area. Later, when squatting alongside a Sharp-tailed Sandpiper (Erolia acuminata) the body size of the Tern was hardly larger than that of the wader, but the longer wings gave it a small margin of superiority in the overall length. Two White-winged Black Terns that were together at Cherry's Swamp on November 24, 1964, appeared to be new arrivals and on December 12, there were three birds. The number had increased to 14 birds by December 20, and another two birds were at the mouth of the Kororoit Creek nearby. Some of these birds showed remnants of recent breeding plumage, mainly by the black blotches on the under wing-linings. One bird at the Werribee Sewerage Farm on December 16, also showed dark markings on the under wings. By December 22, there were 20 White-winged Black Terns at Cherry's Swamp, and 34 birds the next day. The largest number seen together was 42 birds at Cherry's Swamp, on December 24, 1964. Most of these birds appeared to be in the total eclipse-plumage. When first noted, they were speeding low over the water in a compact group and gave the appearance, from a distance, of a flock of waders. Then rising high over the swamp, they circled about for a few minutes before suddenly splitting up and returning to the swamp in a series of spectacular dives, tumbles and side­ slips. They then scattered widely to feed, but frequently during the period of observation they were seen to regroup and repeat the performance. After December 31, 1964, numbers dropped off sharply at Cherry's Swamp and on January 5, 1965, only one bird was seen there. From then until the end of April, 1965, during which time several visits were made to the area, the numbers fluctuated some­ what with a peak of 15 on April 4. Again, as in the first four months of 1964, only one bird attained full breeding plumage. The first indication of the change was 134 DAVIS, Field Notes from South Gippsland [ Bird Watcher noted on January 1, 1965, when the bird showed some black speckling on the under wing-linings and body. By January 29, it had reached the "Dalmatian stage" with larger blotches of black on the same areas. From then on, as the black advanced on the unde wing-linings, under parts and the back, the tail, rump and upper wing-coverts (particularly the lesser wing-coverts) became progressively whiter. On April 3, this bird was almost in complete breeding plumage, but for some white patches on the upper breast, throat, chin and about the head. Twelve days later the bird was in full nuptial dress. Most of the other White-winged Black Terns had remained in what appeared to be the full non-breeding plumage, although, at close range, some dark speckling could be seen on the under wing-linings of some of the birds. Although I heard the birds calling frequently I was not able to add anything of significance to my earlier notes on the calls of the species. Whiskered Terns (C. hybrida), during the period under notice, were relatively scarce and on nearly all of my visits to Cherry's Swamp, they were outnumbered by the White-winged Black Terns. REFERENCES ALEXANDER, W. B. 1928, Birds of the Ocean, 189, pl. 37. AMIET, L. 1956, " Re-appearance of the White-winged Black Tern on the Queensland Coast", The Emu, 56 : 95-99. AM JET, L. 1957, "Further records of the White-winged Black Tern at Raby Bay, Queensland", The Emu, 57 : 55-57. BOURKE, P . A. and LOWE, V. T. 1960, "A sight record of the White- winged Black Tern in Victoria", The Emu, 60 : 65 . CAYLEY, N . W. 1961 , What Bird is That? 249. FITTER, R. G. R. 1952, A Pocket Guide to British Birds, 107. pis. 102-103. GIBSON-HILL, C. A. 1949, Birds of the Coast, 157 and 160. HAMILTON, F. M. 1957, "The White-winged Black Tern in Moreton Bay, Queensland", The Emu, 57: 147-150. HENRY, G. M . 1955, A Guide to the Birds of Ceylon, 329-330. HoLLOM, P . A. D. 1962, The Popular Handbook of British Birds, 273-6, pis. 62, 63, 128. PETERSON, R ., MOUNTFORD, G. and HOLLOM, P. A . D . 1961, A Field Guide to the Birds of Britain and Europe, 149 and 152, pl. 40. SERVENTY, D. L. and WHITTELL, H. M . 1951. Birds of Western Australia, 127. WALL, L. E. 1963, " A Tasmanian record of the White-winged Black Tern", The Emu, 62 : 265-6. WITHERBY, JOURDAIN, TICEHURST and TUCKER. 1948 , The Handbook of British Birds, 5 : 2-11 , pl. 126. Field Notes from South Gippsland By WILLIAM A. DAVIS, Melbourne The following are observations made of species, other than those belonging to the wader group, during a trip to South Gipps­ land during February, 1963. This paper is intended as a second part to " A Wader Survey of South Gippsland Beaches", The Australian Bird Watcher, Vol. 2, p. 48. Complete details of the trip, map and habitats, are given in that paper and will not be reiterated.