VOL. 8 (7) SEPTEMBER, 1980 205

Birds of Victoria Downs Station and of Y arralin, Part 2 By CON BOEKEL, Ngukurra, , vm Darwin, Northern Territory, 5791.

Yellow-tinted Honeyeater Very common in all habitats except Spinifex Woodland and Shrub Thickets. Birds sometimes fed on insects displaced by a rise in river level, clambering over rocks to do so. Breeding: six records date from July 20, when birds were feeding fledglings to October 31 when the first shreds of spider web were being added to a nest. Black-chinned Honeyeater Essentially a bird of the tree canopies wherever there are eucalypts but also seen in paperbarks and Poincianas. Fed once on the flowers of the Blue Pea bush. However it gets most of its food by gleaning the outer­ most leaves. The birds were seen preening each other. Another bird, threatened by a Goshawk, kept still except for the head which was swayed gently from side to side. In view of the recent interest in "helpers" with relation to breeding the following notes are of interest dated July 25, 1976 on the Victoria River. The birds were first noted when oae called and a group of them flew from one gum to another. Oae of these was apparently feeding. The head was moved up, back and down repeatedly. When a full bill of spider web had been collected this bird flew away. As it did so it was joined by three adults. All four landed in the first tree where nest building was in progress. When the builder left this tree, it did so with a distinctive "chip, chip, chip" call. The other three immedi­ ately flew with the bird. When it reached its destination, the call was changed almost immediately to "tnt, tru, tru ... " characteristic of the Black-chinned Honeyeater. In all spider web was collected three times from the same location. The pattern evolved where only one bird at a time seemed to be doing the collecting and construction but it was accompanied in all its activities by the other three birds. It is not known whether the same bird did all the work or whether the birds took it in turn. During this event another bird was seen, an immature. Although it fed among the flowers of the nest tree there was no interaction between it and the other birds. It did not take part in the nest-building. However the presence of this bird and other immatures noted in the previous week, suggest the group may have been preparing for a second clutch. The builder at one stage sat in the nest, turned around in it and worked the nest with its bill. The nest was completely hidden by leaves. It was about eight metres above the ground, one metre from the top of the canopy and a metre in from the edge of the canopy. The nest tree was ten metres from the nearest tree and fifty metres from a dry anabranch of the Victoria River. There was noticeably more intra-specific aggression than normal. The builder·-bird did not seem to be involved. The only inter-specific aggres­ sion occurred when a group of Yellow-tinted Honeyeaters entered the AUSTRALIAN 206 BOEKEL BIRD WATCHER nest tree. They were harried until they left the tree. Birds flying close, but not into the tree, were left alone. The only other visit to the locality on August 2 revealed a brooding bird, three adults, and a single immature still in the vicinity. On August 11 two fledglings were being fed by three or possibly four adults in the fringing vegetation of the Wickham River. White-throated Honeyeater This has a similar distribution to the preceding species. However while the Black-chinned is relatively uncommon along the the White­ throated is relatively common. It was feeding fledglings on November 4, 1976. Brown Honeyeater Generally very common in locations which have some shrub com­ ponent but decreasing in density in shrubs away from water. It is present throughout the year with some contraction of range during The Dry. Bar-breasted Honeyeater Rare on the margins of water generally, it is not present throughout the year. Its presence may be expected in flowering trees particularly paperbarks. Rufous-throated Honeyeater Very common in areas of dense growth in depressions and along water generally. It readily feeds on water-emergent annuals. It bathes fre­ quently during the day. The cattle destroy much of its habitat during The Dry and so it concentrates about the major rivers and minor streams. Possibly some birds are forced out of the area entirely, but there are always some present. Breeding: fledglings being fed on January 25 and 28, 1976; brooding on eggs January 25, 1976. Banded Honeyeater Present throughout the year in varying numbers. Whenever large patches of trees are flowering the number of birds increases enormously. At such times Banded Honeyeaters outnumber all other honeyeaters put together. Breeding was not proved but some obviously young immatures were seen. Mistletoe bird Present throughout the year, numbers varying with the amount of flowering in the mistletoes. Breeding: fledglings were being fed January 28, 1976, February 12 and March 10, 1977. Red-browed Pardalote Present throughout the year; it occupies the drier areas while the following species occupies the moister ones with a considerable overlap. Many breeding attempts were noted. Digging started about April 30 and adults were still feeding nestlings on August 10. Striated Pardalote Present throughout the year. The more common of the two species. There are more breeding records for this species than for any other. The birds were ready to fly into the nest to feed nestlings even when the observer was standing very close. The nests were easy to see in the sandy beds of the major rivers. Digging started about April 30. Adults were still feeding nestlings on August 10. Painted Firetail This bird was not seen in the study area. Bill Midgely gave an accurate VOL. 8 (7) SEPTEMBER, 1980 Birds of Victoria River Downs 207

The Star Finch is a rare straggler. Plate 58 Photo by B. & K. Richa rds descriptive report of this species located less than twenty miles to the south of the Deep Creek area. He is familiar with the Crimson Finch. Star Finch Rare straggler, presumably via the Victoria River from the North. Parties of less than ten birds in January, August and September. Crimson Finch Present throughout the year. This species shows definite patterns of local movement. In The Dry it is restricted to waterside habitats par­ ticularly cane grass and Pandanus. Towards the end of The Dry the birds form flocks of up to twenty birds. Following the first rains the birds disperse along the rivers and also away from the rivers to where there is tall grass or rank vegetation on the margins of watercourses and billabongs. It is found throughout the year in the homestead gardens and nests freely in buildings. This habit, combined with the splendid plumage, makes it a popular bird. Breeding: building a nest in a hollow of a dead tree on January 30, 1976, brooding on January 27, 1976 and brooding eggs on March 19, 1976. The latter nest had been built amid a bunch of bananas in a garden. The breeding attempt failed when the bananas became over-ripe and collapsed the nest. The nest was subsequently occupied by a Double-barred Finch which bred successfully. It appears that the main breeding season of the Crimson Finch coin­ cides with the time at which rivers can be expected to rise and fall rapidly. The birds nest in hollows of limbs well above the water but are often forced to nest in the crowns of Pandanus and these nests are often washed away. The birds' eagerness to build in buildings may reflect a preference for flood-safe nest sites. AUSTRALIAN 208 BOEKEL BIRD WATCHER

Zebra Finch Present throughout the year but in increasing numbers during The Dry when it is common. Found throughout the study area but relatively uncommon in Spinifex and on the Black Soil Plains. Breeding: nestlings on June 12, 1976 . . Double-barred Finch Common in the Riverine Understorey and waterside shrubbery generally. There is some retreat to the main bodies of water as the ephemeral waters dry up. Clutches of four eggs were being brooded on February 26 and May 14. On May 11, 1976 I touched the entrance of a nest, causing the nestlings to "explode" outward. Fortunately they were capable of flight. A predator would have found the effect of the nestlings hurtling out most confusing. Masked Finch Common on grassy plains particularly the red soil river benches. They build both on the ground and in trees. On April 10 a bird was brooding a clutch of five in a nest situated under a sparse clump of grass. On July 25 , 1977 a bird entered a nest hole in a tree. Groups of adults and begging immatures were noted on the same day. On August 7, 1977 a bird fed nestlings in a nest on the ground. Cattle had eaten all the grass around the nest and it was open to the hot sun. The interior of the nest was very hot and the nestlings listless. A week later they were all dead. Long-tailed Finch Found with the Masked Finch, the more common of the two. On May 3, 1976 a pair made repeated visits to a nest situated in the crown of a Pandanus. Pictorella Mannikin More common in The Dry than in The Wet. The characteristic finch of the Black Soil Plains. It has the surprising habit of foraging in the shallow water at the receding margins of the billabongs. Algae were being picked up in the bills but the birds may have been searching for softened seeds or even insects. Breeding not proved but large numbers of immatures were often present. Chestnut-breasted Mannikin Uncommon in rank vegetation about water including Pandanus, cane grass, dense Riverine Understorey and Shrub Grassland. Sightings fell mainly between November and February with odd sightings in between. One flock contained immature Chestnut-breasted Mannikins as well as the following species. Y ellow-rumped Mannikin Less common than the preceding species and on all occasions except one seen in its company. Gouldian Finch Seen in small numbers in Savanna Woodland. A flock of seventy-five fed for a few days in May 1976 in a grassy area in the river-bed of the Wickham. It is probably entirely absent from the study area on some occasions. Olive-backed Oriole Thinly scattered in the Riverine Canopy and Understorey, particularly VOL. 8 (7) SEPTEMBER, 1980 Birds of Victoria River Downs 209

Great Bowerbirds common where heavily wooded. P late 59 Photo by B. & K. Richards where there are large stands of Paperbarks interspersed with figs. There is a small influx during The Wet. Birds moving in do not necessarily follow the rivers, they sometimes cross the Spinifex Woodland. Great Bowerbird All habitats; it is common generally but most numerous wh ere most heavily wooded. Bowers were found in most habitats and none lacked some artificial object. White pieces of limestone constituted the most common article, then snail shells and various fruits. A fledgling was being fed on January 25, 1976. Australian Magpie-lark All habitats but most common in the better-watered parts. Some birds are sedentary, while passage flocks occur. A female of a pair which was under daily observation broke a leg. She remained from The Wet and on through The Dry when the number of Magpie-larks generally increased as birds arrived from the south. The pair under observation defended their territory throughout this time. Mud was being collected as early as November 30 and nestlings were fed as late as February 14. White-breasted W oodswallow Present throughout the year; nearly always near the larger and more permanent billabongs but sometimes near the rivers. Flocks numbered less than twenty. This species would fly close to the observer catching disturbed flying grasshoppers. It nested in Mistletoe clumps in Coolabahs and in disused nests of Magpie-larks. A bird was brooding on October 28; nestlings were still being fed on November 19. All four nests were found on the margins of Crocodile Billabong. AUSTRALIAN 210 BOEKEL BIRD WATCHER

Masked W oodswallow This species is regularly present in large numbers from about May to July particularly where there are large areas of eucalypts in flower. White-browed W oodswallow Single birds seen amongst the larger flocks of the preceding species. Black-faced Woodswallow Probably the most successful of all the birds in the study area. It is present throughout the year and very common in all habitats at some time or other. It has a marked ability to benefit from whichever food source is abundant at any given time, catching insects on the wing and on the ground, foraging in trees and feeding on nectar or pollen of flowering trees. It seems that the first rains of The Wet trigger breeding as there is a burst of activity and nest building starts soon afterwards. In The Dry it forms post-breeding flocks which move locally from one food source to another. These flocks are often joined by numbers of White-winged Trillers. Breeding: copulating on November 11, 1976 and feeding fledg­ lings on February 12 and 26, and March 9, 1977. Little W oodswallow In The Wet this species is concentrated along the escarpments and over Spinifex Woodland. Some stay in these habitats during The Dry but there is a tendency to spread over the rest of the study area and in particular over the main bodies of water, especially where these abut cliffs. Breeding was not proved, but much observed behaviour, as well as some gawky immatures, suggests that breeding does take place in the study area. Pied Butcherbird Common along all waterways and waterside vegetation. Uncommon in Woodland Savanna and rare in Spinifex Savanna. Nest-building, and begging immatures, were noted. Crow Species An incorrect set of characteristics was used for Crow spec1at10n. Crows were common; on February 20 one was seen feeding a fledgling ChanneJ,-billed Cuckoo. Conclusion The study area, with 181 bird species, of which sixty-four are known to breed, is rich both in numbers and diversity. The only known breeding of the Channel-billed Cuckoo and the Yellow-billed Spoonbill in the Northern Territory was recorded during the study period. The known northernmost or southernmost distribution of many of the species in the western third of the Territory has been extended. It is one of the few areas which still maintains a population of the western subspecies of the Purple-crowned Fairy-wren. Of special interest is the Deep Creek area which contains species found nowhere else in the study area, i.e. Blue-faced Honeyeaters, Silver­ crowned Friarbirds, Leaden Flycatchers, Green-backed Gerygones and White-quilled Rock-pigeons. Future surveys of the Victoria River avi~ fauna should include the Deep Creek area for these species, as they will probably be among the first to go as a result of environmental degradation. Bird populations which could be used to test the progress of degradation in the large rivers include White-browed Robin, Lemon-breasted Fly­ catcher, Northern Fantail and Purple-crowned Fairy-wren. VOL. 8 (7) SEPTEMBER, 1980 Birds of Victoria River Downs 211

The Victoria River seems to be a flyway for many birds, particularly for waterfowl. A goodly number of waders was recorded. Dominating all life in the study area are The Wet and The Dry climatic periods. For most birds, ranges expand and contract and suit­ able habitats appear and disappear with these seasons. Breeding and movements are on the whole closely related to the two seasons. Towards the end of The Dry the stressing effects of climate are aggravated by cattle. They also concentrate about water and it is then they have their most direct impact on birds. The birds which depend on grassy habitats are rendered homeless. Birds find the understorey eaten or broken down; their source of food and cover destroyed. Alien plants, Parkinsonia and burrs, find an entry and create new habita:ts which very few birds can use.

Acknowledgements I wish particularly to thank Dr. G. Storr for his generous help with the scope of this paper, on determinations and for checking the results. Mr. Howard Jarman also gave much assistance. Many people of Victoria River Downs and Yarralin gave information. I mention particularly Messrs Bill Midgely, Kerry Slingsby and Daly Bulgara. Finally, thanks are due to the manager of Victoria River Downs for permission to roam freely, and to the traditional owners of Yarralin for allowing me free access to their land.

References Campbell, A. J., 1974. Nests and Eggs of Australian Birds Vols. 1 & 2, Wren, Melbourne. Cayley, N., 1964. What Bird is That? Angus & Robertson, Sydney. Cogger, H. G., 1975. Reptiles and Amphibians of , A . H. & A. W. Reed, Sydney. Foran, B. D., & Hill, B., (undated). Victoria River Range Herbarium, Primary Industries Branch, N.T. Lake, J. S., 1971. Freshwater Fishes and Rivers of Australia, A. H. & A. W. Reed, Sydney. Macdonald, J. D., 1973. Birds of Australia, A. H. & A. W. Reed, Sydney. Slater, P., 1970 & 1974. A Field Guide to Australian Birds Vol. 1 & 2, R igby, Adelaide. Storr, G. M., 1977. Birds of the Northern Territory, West Australian Museum, Pub!., Perth. Storr, G. M., & Johnstone, R. E., 1975. An Observation of the Pheasant-tailed Jacana in Wetesrn Australia, W. A. Nat. 13 (2/ 3). Sweet, I. P., 1973. 1:250,000 Geological Series Explanatory Notes, Victoria River Downs. Australian Government Publishing Service.

ABW