AUSTRALIAN 128 FRITII WATCHER nest in upland tropical rainforest, classified as simple notophyll vine forest by Tracey (1982), near Paluma Village on the Paluma Range (l9°00'S, 146°10'E), north-eastern Queensland, c. 80 km north of Townsville. It has appeared previously in Frith & Frith (1991: 51; 1992: 47). The photograph (Plate 38) shows an adult Noisy about to deliver a bill full of about six litpp, apparently dead tiger leeches to its brood of three half­ developed nestlings in mid December 1981. I took a photograph of this bird and/ or its mate with a bill similarly full of dead leeches on at least four other occasions. Given the difficulty experienced by people in killing a single leech, it would be interesting to see how adult achieve the acquisition of six or more leeches. Are previously caught leeches put aside while the next is killed, or is each caught and killed with previously captured leeches already in the bill? As I believe leeches to be rarely recorded as eaten by in Australia (Barker & Vestjens 1990 recorded no instance), I note that the Grey-headed Robin Heteromyias albispecularis (Petroicidae) has been recorded doing so, in the same habitat as the (Frith & Frith 1999). Although Rose (1999) mentioned skinks (Squamata: Scincidae) as having been recorded as eaten by the Rainbow Pitta Pitta iris, both he and Erritzoe & Erritzoe (1998) did not mention skinks as food of the Noisy Pitta. I therefore note that I took one picture of one of the parent Noisy Pittas, at the same nest as above, feeding a tail-less medium-sized skink to their nestlings.

References Barker, R.D. & Vestjens, W.J.M. (1990), The Food of Australian Birds 2, , CSIRO, Melbourne. Erritzoe, J. & Erritzoe, H.B. (1998), Pittas of the World, A Monograph of the Pitta , Lutterworth, Cambridge. Frith, C. & Frith, D. (1991),Australia's Cape York Peninsula , Frith & Frith, Malanda. --& --(1992), Australia's Wet Tropics Rainforest Life, Frith & Frith, Malanda. Frith, D. & Frith, C. (1999), 'The nesting biology of the Grey-headed Robin, Heteromyias albispecularis (Petroicidae), in Australian upland tropical rainforest', Emu 99, in press. Rose, A.B. (1999), 'Notes on the diet of the Noisy Pitta Pitta versicolor in New South Wales', Aust. Bird Watcher 18, 42-43. Tracey, J.G. (1982), The Vegetation of the Humid Tropical Region of North Queensland, CSIRO, Melbourne. By CLIFFORD B. FRITII, 'Prionodura: P.O. Box 581, Malanda, Queensland 4885 Received 18 March 1999 •

Australian Ravens Preying on a Banded Stilt

Rottnest Island lies 20 km off the coast of at about the latitude of Perth. A major feature of the island is a system of lakes at its eastern end, the largest two being Government House Lake and, to its north, Lake Herschel. These are separated by a tarmac causeway for about 100 m. Some 20 m from the western end of the causeway, a small triangular spit, 10m along each side, protrudes into VOL.18 (3) Australian Ravens SEP1EMBER 1999 Preying on Banded Stilt 129 the former lake. The spit is sparsely covered with low (about 0.3 m) scrubby vegetation. On 8 October 1998 we bird-watched along the causeway, the main points of interest being some 200 Banded Stilts Cladorhynchus leucocephalus feeding in Lake Herschel and at least 50 Ruddy TurnstonesArenaria interpres scattered along the nearest shore of Government House Lake. While walking eastwards along the causeway and about halfway along it, we noticed two Australian Ravens Corvus coronoides harassing an adult Banded Stilt. All birds were flying westwards parallel to the causeway, the Stilt along the Government House Lake edge with one Raven above and directly behind it and the other rather lower and to its left. Whenever the Stilt veered towards the water, the Ravens closed on it, forcing it to follow the causeway. When the trio reached the small spit, the Ravens forced the Stilt to ground. One Raven then perched on the top of the telegraph pole on the spit; the other two birds vanished into the vegetation. Intrigued, we walked quickly to the spit. Our arrival there disturbed the Raven on the ground which joined its partner on the telegraph pole. The Stilt, however, did not reappear. It was found, apparently in some distress, trying to stand up and walk but constantly tripping on the vegetation. KR shepherded it towards the water. As soon as it reached the lake's sandy edge, it was clear that it was unharmed. It ran the last metre or so to the water. The Ravens pursued it immediately but the Stilt was now in control of the situation; it flew out in a big circle low over the water, closely chased by the Ravens, and returned to the causeway to cross it at right angles. It touched down on Lake Herschel in the middle of the flock of feeding Stilts. The Ravens then gave up the chase. On the spit where the Stilt had been grounded, we found 50 to 60 (only a rough count was made) Banded Stilt feathers. Some were clearly adult breast­ band feathers. Most feathers were separate, but there was at least one clump of feathers which appeared to have been plucked as a group, being stuck together at their base. We infer that all feathers were plucked by the bill but cannot be sure as we did not see the attack. Rowley & Vestjens (1973) gave the diet of the Australian Raven as carrion (34% ), insects ( 42%) and plants (24% ). Barker & Vestjens (1990) gave a systematic list of Raven food items. Corvidae are, however, known to have 'definitely predatory tendencies' (Coombs 1985). Several cases of Australian Corvidae eating vertebrates have been reported, but it is often not clear whether the birds have killed the prey or found it as carrion. Cases of observed predation of birds by Australian Ravens include: young Galahs Cacatua roseicapilla (by a group of Ravens), Common Starling Sturnus vulgaris in flight, and an adult Noisy Miner Manorina melanocephala, reported by Rowley & Vestjens (1973); a Common Starling in flight reported by Lepschi (1992); a nearly fledged Australian Magpie Gymnorhina tibicen chick held down and whose head was pulled off, reported by Hawtin (1997); and, finally, AR saw an unfledged Australian Wood Duck Chenonetta jubata duckling snatched by a single Raven which outwitted the two adult guardians of the brood of 13 ducklings. Other cases of predation on birds by Australian corvids include the following. Talmage (1986) reported three cases of predation by Little Ravens Corvus mellor! in a suburban Melbourne park: a pair forced a Spotted Turtle-Dove Streptopelia chinensis to the ground where it was killed; a single Raven twice knocked a flying Budgerigar Melopsittacus undulatus to the ground and eventually killed it by AUSTRALIAN 130 ROGERS & ROGERS BIRD WATCHER repeated stabs to the head with the bill; and a ground-feeding Common Myna Acridotheres tristis was killed by an adult Raven 'flying down onto ... it'. Prytherch (1995) reported a Little Raven landing on the back of a feeding Spotted Turtle­ Dove, killing it with jabs of the to head and neck, and flying off with the head. Fell (1987) reported Forest Ravens Corvus tasmanicus killing Little Penguins Eudyptula minor by pecking. out their eyes . The preferred method of raven predation would seem to be to force the prey to the ground by attack from above and kill it by repeated pecks to the head and neck. The Rottnest Island attack against the breast might have happened because of how the Stilt landed in the vegetation, and the Raven may have been wary of the needle-like bill. The head seems to be the preferred food item, but possibly the head is the easiest part of the prey to detach and carry. Attacks may be made by single ravens or by groups of two or more birds acting together. Intensely gregarious birds like Banded Stilts are thought to enhance their ability to escape predators by flocking (Morse 1985). Individual Banded Stilts may be particularly vulnerable to predation; this notion is supported by the observations of Robinson & Minton (1989) who reported both predation of Banded Stilt eggs and a 99.5% predation rate of chicks by Silver Gulls Larus novaehollandiae in the later stages of the breeding cycle. An intriguing speculation is that the co-ordinated predation of Banded Stilts is a learned behaviour of the Ravens of Rottnest Island. Serventy & Whittell (1951) reported that Banded Stilts were 'preserved' [sic) for the governor's shooting parties when he maintained a summer residence on the island. Possibly the Ravens acquired a taste for Stilts by preying on wounded and isolated birds. It would not have taken them long to realise that even healthy Stilts have almost no defences against aggression. We thank Danny Rogers for help in the preparation of this note. Our thanks too to Stephen Debus and Khalid Al-Dabbagh for help in locating references.

References Barker, R.D. & Vestjens, W.J.M. (1990), The Food of Australian Birds 2, Passerines, CSIRO, Melbourne. Coombs, C.J.F. (1985), 'Crows', in Campbell, B. & Lack, E. (Eds), Dictionary of Birds, Poyser, Calton and Verm11lion. Fell, P.J. (1987), 'Forest Ravens preying on Fairy Penguins',Aust. Bird Watcher 12, 97. Hawtin A. (1997), 'Corvids taking live prey', Bird Observer 780, 11. Lepschi, B.l (1994), 'Australian Raven predation on Common Starling',Aust. Bird Watcher 15, 211. Morse, D.H. (1985), 'Flocking', in Campbell, B. & Lack, E. (Eds), Dictionary of Birds, Poyser, Calton and Vermillion. Prytherch, J. (1995), 'Paradise lost', Bird Observer 757, 4. Robinson, A. & Minton, C. (1989), 'The enigmatic Banded Stilt', Birds International 4(1), 72-85. Rowley, I., & Vestjens, W.J.M. (1973), 'The comparative ecology of Australian corvids. V. Food', CSIRO Wild/. Res. 18, 131-155. Serventy, D .L. & Whitten, H.M. (1951 ), Birds of Western Australia, University of Western Australia Press, Perth. Talmage, M.E. (1986), 'The Little Raven as a predator', VORG Notes 22, 3-9.

By KEN G. ROGERS and ANNIE ROGERS, 340 Ninks Road, StAndrews, Victoria 3761 Received 3 December 1998 •