VOL. 17 (2) JUNE 1997 81 AUSTRALIAN BIRD WATCHER 1997, 17, 81-86 Notes on Sanford's Sea-Eagle Haliaeetus sanfordi and Other Raptors in the Solomon Islands by JERRY OLSEN, Applied Ecology Research Group, Faculty of Education, University of Canberra, P.O. Box 1, Belconnen, A.C.T. 2616 There are few published reports on raptors in the Solomon Islands (Brown & Amadon 1968; Schodde 1977; Hadden 1981; Cade 1982; Coates 1985; Fentzloff1989, 1990; Blaber 1990; Webb 1992, 1997; Gibbs 1996). In September 1990 I visited the Solomon Islands mainly as a tourist but also to look for Sanford's Sea-Eagle. Fourteen raptor species breed there and I report here on the eight raptor species I saw, and in some cases photographed, on the islands of Guadalcanal, in Guadalcanal Province, and Ghizo, Kolombangara and Kohinggo in the Western Province. The Solomon Islands are a scattered double chain of 992 islands, atolls and cays just south of the Equator, extending 1646 km in a south-easterly direction from Bougainville Island in Papua New Guinea. The six major islands, Guadalcanal, New Georgia, Malaita, Santa Isabel, Choiseul and Makira, vary in length from 87 to 171 km and in width from 25 to 50 km. The country's highest peak Makarakombu (2447 m) is on Guadalcanal and the islands are covered in dense rainforest, with mangroves, swamps and coconut plantations on the coasts. Rainfall averages 3500 mm but is closer to 6 m a year in many areas. Eleven diurnal and three nocturnal raptors breed in the Solomon Islands (Appendix 1 gives scientific names). Of these, Sanford's Sea-Eagle, Imitator Sparrowhawk and Fearful Owl are threatened (Collar et al. 1994). Systematic list Osprey Pairs of Ospreys nested in high densities on the coasts of Ghizo and Kolombangara. They were less common on the north coast of Guadalcanal where, when travelling by road, I saw only one nest between Honiara and Cape Esperance. This may be because the north Guadalcanal coast is heavily populated and covered with many coconut plantations. In addition, Guadalcanal has one of the highest, perhaps the highest, rate of malarial infection in the world and I saw DDT used there to spray huts. The spray canisters were rinsed in creeks and rivers that flowed onto the north coast. Raptors that eat other birds or large fish tend to be more affected by pesticides than those species that feed on mammals or insects (Newton 1979). Ospreys prey on large fish and may be affected by pesticides. The one nest located on 28 September near Cape Esperance, on the north-western comer of Guadalcanal, had parents feeding one flying young. On Ghizo and Kolombangara, where there were many nest trees, nests were 1.5 to 2 km apart. Ospreys were seen on three occasions fighting with other Ospreys, and once on a mountainside 1 km inland, with a raptor that could have been a Meyer's Goshawk. I saw no nests farther than 200m inland. Nests were often high on exposed limbs in dead trees. Ospreys were not persecuted and they nested in villages. One nest near Vanga Point on Kolombangara was at the top of a high tree, which the villagers called 'Pepeo', in a farmer's garden. The landowner said the pair fledged its single young in August that year. Teu Zhingihite, a village leader on Kolombangara (who also guided Jared Diamond during his research there), has observed birds in the area for 50 years. He said that Ospreys, and other raptors there, laid one egg and fledged one young each year. This was the case for Ospreys and the three other raptor species (Varied Goshawk, Bam Owl and Brahminy Kite) which I saw with young on Kolombangara. Webb (1997 and pers. comm.) has seen broods of two and three Varied Goshawks on Santa Isabel, but found clutches and broods of one more common. Brown Goshawks on Rennell may have broods of two young (Buckingham eta!. undated). AUSTRALIAN 82 J. OLSEN BIRD WATCHER Pacific Baza These were fairly common in coconut plantations and villages. One pair hunted in the town of Ringgi on Kolombangara on 25 to 28 September but I found no nest. They were large, slow-flying hawks with heavily barred underparts, apparently of the subspecies Aviceda subcristata gurneyi. They had flight action similar to a pigeon, were tame, and appeared to forage in the tree canopy. Brahminy Kite These kites nested cornnfonly along the shoreline in the same coastal habitat as Ospreys. On Kolombangara nests were about 1.5 to 2 krn apart as with the Osprey. I saw no conflict between Ospreys and Kites even at one site where the Ospreys and Kites nested about 40 m apart in a village. As with Ospreys, villagers did not molest them. Nests were in live trees and were lower and more surrounded by foliage than were nests of Ospreys. One on Kolombangara was 20 m up in the fork of a tree that natives called 'Magroo'; on 20 September the female was brooding a single downy young less than a week old. As reported by Bell (1985), these kites commonly foraged under the canopy in rainforest high on mountainsides 1.5 krn inland. They behaved like forest buteos, e.g. Red-shouldered Hawks Buteo lineatus. I saw no Kites nesting in the forest. Sanford's Sea-Eagle This eagle is the largest avian predator in the islands and, unlike Brahrniny Kites and Ospreys, it was killed by locals because it was.said to catch dogs, cats, poultry and other animals valued by these villagers. Australian Catholic priests at Vanga Point apparently shot the local eagles as part of their teachings about raising poultry and other stock. In pre-Christian times Sanford's Sea-Eagle was worshipped as a totem and, therefore, not killed. This changed as values and beliefs changed. Locals also told me that the Sea-Eagles catch many possums, and do this sometimes by landing on the trunk of a tree and grabbing the possum as it comes out. Some villagers thought that eagles frightened possums out by scratching the trunk, whereas others said that possums carne out because eagles spread their wings over the hollow so possums thought it was night (they apparently are nocturnal whereas the eagle is diurnal). The former explanation seems more likely than the latter. Villagers also said that eagles robbed Brahrniny Kites and Ospreys of fish, so these smaller species fought with and drove away eagles corning down from the mountains to the shoreline. I saw no Sea-Eagles on the shoreline of any island, though I spent three full days searching from motorised canoe. Some raptors that locals pointed to and called Sea-Eagles were juvenile Brahrniny Kites fishing or soaring on hillsides. The Kites were about the same colour as Sea-Eagles and looked large in certain environments. On 22 September at 1600 h I saw a Sea-Eagle soaring high up on the flanks of Mt Mbatuvana on Kolombangara. The eagle was very like a juvenile White-bellied Sea-Eagle Haliaeetus leucogaster or a large, heavy juvenile Brahrniny Kite. It soared with the characteristic V -shaped dihedral of the White-bellied Sea-Eagle, giving the impression of a very heavy-bodied bird, and had a very short tail and shorter wings than White-bellied Sea-Eagles with which I am familiar near Canberra. On 24 September I travelled in a truck from the local forestry operation to a point 350 m up Mt Rano on Kolombangara. I travelled to a small deforested patch there on the assumption that it may be easier to find the eagle in remnant, as opposed to continuous, tracts of rainforest. At 1000 h a Sanford's Sea-Eagle flushed from a dead possum along the side of the road in front of us and flew to a tree where I photographed it (Plate 7). Again, the eagle looked like a juvenile White-bellied Sea-Eagle though the colouring was different. The bird did not look like that in Plate 29 of Brown & Amadon (1968), the only pictorial representation I could find of the eagle. Its tail was much shorter than that shown in Brown & Amadon, and its body shape, when perched, was similar to that of the Palm-nut Vulture Gypohierax angolensis (also pictured on Plate 29 of Brown & Amadon) as the wings extended well past its short tail. The bird perched upright like the vulture depicted and unlike the Sanford's Sea-Eagle depicted. The colour also was different. It was overall a slaty, sooty dark brown with a lighter tan-coloured face and throat and a bare patch behind its beak. The eagle had a full crop, apparently of possum, that protruded white through the brown and tan feathers of the upper breast. The beak was laterally flattened as in White-bellied Sea-Eagles, and the bird flew in a similar slow, heavy fashion but on shorter wings that appeared wide near the body, i.e. the secondaries were longer or appeared longer because the primaries of this individual were shorter than in the White­ bellied Sea-Eagles I had observed. It flew to a logged clearing farther up the road where it perched for the afternoon. It did not seem to have the agility of a forest eagle and showed some reluctance to leave the clearing when I flushed it. My impression was that it could hunt over clearings, roads, rivers and the shore but could not easily hunt in dense rainforest. Except for colouring, the bird was ve!"Y similar to a White-bellied Sea-Eagle.