VOL. 9 (1) MARCH, 1981 KLAPSTE: Caching of food, White-winged Clough 25
E. sacra is common along the adjacent mudflats, and accustomed to man, even to the extent of stealing fish from a nearby fisherman's bucket; it can normally be approached closely before it flies. On this occasion however the bird appeared to be extremely cautious, even furtive, in its movements. It approached the stream slowly, and looked carefully around before bathing. It remained semi-submerged for a few seconds, and after each immersion immediately stood upright, with neck outstretched and crest fully erect, 'glaring round' in all directions. Brief but vigorous feather-shaking followed, and after another survey of the area, the process was repeated, about five times in all. No preening, stretching or drying took place, and the bird flew off directly afterwards.
Vestjens suggests that bathing serves to cool as well to to cleanse, and describes accompanying gular fluttering. Here no gular fluttering took place; the temperature was about 25°C, with high humidity, average for the time, season and locality.
The apparent caution of the bird, which contrasted with its normal character, and with the behaviour of the waders, is puzzling. Hutson (1956, The Ornithologists Guide, B.O.U. : 102 suggests that 'different bathing methods are linked with the degree of danger from predators to which the bird is exposed at such times', but it is difficult to see why the Egret should have felt itself in danger in this situation.
By MICHAEL BARTLETT, Evangelisches Krankenhaus, 4520 Melle, W. Germany. ABW
Caching of Food by the White-winged Chough
The function of food-hiding or food-storing by birds, the so-called caching, is to provide a reserve against the time when food will be less abundant.
Together with Peter Klapste I observed the caching of food by a group of White-winged Choughs Corcorax m elanorhamphos at the main picnic area near Lake Hattah within the Hattah-Kulkyne National Park in north-western Victoria.
On the morning of 20 September 1980 I was feeding White-winged Choughs with scraps of bread at the above locality. A group of eight birds was involved, consisting of both adults and juveniles. At 0915 hours I noticed one bird - a juvenile - hide a scrap of bread in soft sand about 30 m from the spot where it was picked up. During the following fifteen minutes we watched all the birds cache this food in the same way. Usually they carried it in their bills, all flying in the same direction, for about 100m before caching it. AUSTRALIAN 26 DEBUS: Square-tailed Kite flight display BIRD WATCHER
All the birds hid the food in the same general area, but in different locations. However, it is questionable whether the Choughs are eventually able to recover all pieces of such hidden food. An Australian Raven Corvus coronoides also took some of the scraps of thrown bread. We did not see it cache food, but this species has been recorded as doing so by Rowley (1973, CSTRO Wildlife Res. 18: 25-65). Our observed Raven usually carried the bread in its bill, alighted in shallow water about 30 mm deep near the edge of the lake, put the bread into the water and stood on it, to make it softer, and then ate it on the spot.
By JAROSLAV KLAPSTE, 6/15 Southey Street, Elwood, Victoria 3184.
ABW
Square-tailed Kite Flight Display
The literature contains a number of sight records of the Square-tailed Kite Lophoictinia isura, but little on its behaviour. Its displays appear not to have been described, so this note is an attempt to fill some of the gaps. A pair I observed in late August, 90 km west of Clermont, Queens land, were soaring high together. One, presumably the male, pursued the other on a leisurely zig-zag course. The performance appeared grace fu l and unhurried, with slow wingbeats. No calls were uttered. A. McGill (in !itt.) has also observed a pair in courtship flight in mid-November, near Baradine, N.S. W. In what resembled play behaviour, the birds repeatedly flew towards each other at low altitude, and indulged in some rolling flight and some tumbling action each time they met. Thus the Square-tailed Kite performs mutual soaring and rolling court ship displays as do many raptor species (Brown, 1976) . It would be instructive to know whether it also performs undulating advertisement displays, or whether it carries the courtship display further to the 'cart wheeling' stage as do the milvine kites, e.g. Black Kite Milvus migrans and Brahminy Kite Haliastur indus. Behavioural studies can assist in determining relationships. The biology of the Square-tailed Kite and its probably close relative the Black-breasted Buzzard Hamirostra m elano sternon deserve detailed study.
Acknowledgement I am grateful to Mr. A. R. McGill for freely providing details from his notes, and for some helpful suggestions.
Reference Brown, L. H., 1976. Birds of Prey: their Biology and Ecology. London, Hamlyn.
By STEPHEN J. S. DEBUS, 42 Kenneth Street, Longueville, N.S. W. 2066. ABW