VOL. 13 (4) FRANKLIN & ROBINSON: DECEMBER 1989 Regent Honeyeater, Territorial Behaviour 129 Regent Honeyeater Xanthomyza phrygia Plate 34 Photo: Keith & Beryl Richards Territorial Behaviour of a Regent Honeyeater at Feeding Sites Honeyeater aggression at nectar sources is obvious, and Ford & Paton (1982) demonstrated its significance in partitioning the food supply. Larger honeyeaters tend to dominate smaller species (Ford 1979, McFarland 1986). Honeyeaters may defend nectar sources by establishing territories either temporarily (Ford 1981) or long-term (Paton 1985, Pyke 1985). Alternatively, defence may occur without formal territoriality (McFarland 1986). The Regent Honeyeater Xanthomyw phrygia is aggressive, nectarivorous and either nomadic or migratory (Franklin et al. in press). Most of its nectar is obtained from eucalypts, a source not conducive to the establishment of permanent or long-term territories (Franklin et al. in press). At 43 g weight it is rarely the largest honeyeater present at a nectar flow (unpublished data). Feeding-site territoriality by the species is implicit in the observations of Gould (1865) and Campbell (1945) but has not been formally described. We describe temporary territorial behaviour of a Regent Honeyeater in a remnant stand of Red Ironbark Eucalyptus sideroxylon in urban Bendigo, Victoria. Four and a half hours of observation were spread over seven days between 10 May and 10 August 1986. From 10 May to 30 June a single Regent Honeyeater spent nearly all its observed time in the crown of a blossoming Red Ironbark tree. It appeared to feed almost FRANKLIN & ROBINSON: AUSTRALIAN 130 Regent Honeyeater, Territorial Behaviour BIRD WATCHER exclusively on nectar. It defended this and subsequent feeding areas by attempting to displace (sensu McFarland 1986) intruders - Red Wattlebirds Anthochaera carunculata, Musk Lorikeets Glossopsitta concinna, White-plumed Honeyeaters Lichenostomus penicillatus, two other Regent Honeyeaters and a Blackbird Turdus merula- even when the intruder was unlikely to be seeking nectar. Displacement of single Red Wattlebirds (weight c. 120 g) was sometimes successful, but at other times resulted only in.the Wattlebird moving a short distance within the crown to recommence feeding from blossom. In this case the Regent Honeyeater usually persisted with the attack, sometimes subsequently evicting the Wattlebird; on other occasions it eventually discontinued the attack. Musk Lorikeets arrived in flocks of 4 and 15. Individuals of the smaller flock were attacked and unsettled, but not removed from the crown, and the Regent Honeyeater eventually discontinued the attack. The larger flock was watched closely but not attacked. The single White-plumed Honeyeaters, two Regent Honeyeaters and Blackbird were evicted. On 12 July the few remaining flowers appeared spent, and the Regent Honeyeater alternated between the crown and the crown of another, still blossoming Red Ironbark 30 m away. Only one intruder, a Red Wattlebird, was observed to enter the second feeding site during one hour's observation, and was evicted. The Regent Honeyeater promptly left its second site to attack a White-plumed Honeyeater and a Blackbird when they entered its first feeding site. On 20 July the second feeding tree had been felled . The Regent Honeyeater occupied the crowns of several smaller Ironbarks close by, part of a larger stand with low levels of flowering, and still within sight of its original feeding tree. Its occupancy was unchallenged even though, as on 12 July, Noisy Miners Manorina melanocephala and Red Wattlebirds fed only a few metres away. It left this third site only once in an hour - to attack two other Regent Honeyeaters when they entered its original feeding tree. This third site was still occupied on 10 August. Aggressive display (in lieu of attack?) was noted on 16 June. The Regent Honeyeater flew up to a Red Wattlebird, landing close and facing it with their beaks almost touching. The Regent Honeyeater drooped its wings, held its tail slightly fanned and bobbed up and down, calling as it did so, for 30 seconds. The Red Wattlebird took note of this behaviour, but did not move until after the Regent Honeyeater had moved away. It then left the tree without having fed. The call uttered by the Regent Honeyeater during the display was similar to, but more agitated than, the commonly uttered and apparently territorial call. The normal call is also accompanied by head-bobbing or bowing (Campbell 1901, North 1906, pers. obs.). Intimidatory displays have been recorded in Noisy Miners (Dow 1975), New Holland Honeyeaters Phylidonyris novaehollandiae (Rooke 1979) and the Eastern Spinebill Acanthorhynchus tenuirostris (McFarland 1983). A peak of aggressive activity was noted on 16 June, when in one hour the Regent Honeyeater made 17 attacks and was itself attacked 3 times. Paton recorded an average of 2.2 aggressive acts per hour in territorial New Holland Honeyeaters (1980), and between one and 26 intrusions per hour into their territories in another instance (1985). The largest of the Regent Honeyeater's territories was estimated to be 150 cubic metres, generally much smaller than that recorded by Paton for New Holland Honeyeaters, but similar to that recorded by Ford (1981) for a Red Wattlebird. The Regent Honeyeater has previously been recorded attempting to exclude larger honeyeaters (Red Wattlebirds, Noisy Miners, Noisy Friarbirds Philemon comiculatus and Little Friarbirds P. citreogularis) as well as several normally non-nectarivorous birds, from feeding sites (Campbell1945; various observers, pers. comm.). Territorial New Holland Honeyeaters had difficulty evicting Red Wattlebirds, but interfered with VOL. 13 (4) FRANKLIN & ROBINSON: DECEMBER 1989 Regent Honeyeater, Territorial Behaviour 131 Noisy Friarbird Philemon corniculatus Plate 35 Photo: Keith & Beryl Richards their feeding (Paton 1980). Territorial behaviour may improve a bird's chances of excluding a larger bird from a food source (Franklin et al. 1987). Aggression by the Regent Honeyeater towards non-nectarivorous birds is consistent with the apparently indiscriminate aggression noted in Noisy Miners (Dow 1CJ77), Bell Miners Manorina melanophrys and Yellow-tufted Honeyeaters Lichenostomus melanops (Wykes 1985) . Though well known as an aggressive species (e.g. Gould 1865, North 1906), there are also numerous observations of Regent Honeyeaters being attacked by other larger and smaller honeyeaters, behaving furtively as if to avoid aggression, and co-existing amicably with other honeyeaters (Franklin et al. in press and pers. obs.). Clearly the species' strategy in gaining access to food varies from situation to situation. The establishment of temporary territories is one such strategy. The use of numbers to both swamp and monopolise nectar sources may be another (Franklin et al. 1987 and in press). The factors that influence this variation in strategy are not well understood for any honeyeater, but are likely to be important in developing a conservation program for this declining species. We thank Bill Flentje for drawing our attention to the presence of Regent Honeyeaters at the site, Peter Menkhorst for his assistance and encouragement, and Hugh Ford for his constructive comments. References Campbell, A.G. (1945), 'Birds of my garden (part 9)', Bird Observers Club Monthly Notes, Oct. 1945. Campbell, A.J. (1901), Nests and Eggs of Australian Birds, privately published, Sheffield. Dow, D.D. (1975), 'Displays of the honeyeater Manorina melanocephala', Ziet. Tierpsychol. 38, 70-96. --(1977), 'Indiscriminate interspecific aggression leading to almost sole occupancy of space by a single species of bird', Emu 77, 115-121. furd, H.A. (1979), 'Interspecific competition in Australian honeyeaters- depletion of common resources', Aust. J. Ecol. 4, 145-164. -- (1981), 'Territorial behaviour in an Australian nectar-feeding bird', Aust. J. Ecol. 6, 131-134. --& Paton, D.C. (1982), 'Partitioning of nectar sources in an Australian honeyeater community', Aust. J. Ecol. 7, 149-159. CHATTO: AUSTRALIAN 132 Maned Ducks, Large Brood BIRD WATCHER Franklin, D., Menkhorst, P., & Robinson, J. (1987), 'Fighting, form and function in honeyeaters', RAOU Newsletter 14, 1-2. --, --& --(in press), 'Ecology of the Regent Honeyeater Xanthomyza phrygia', Emu 89. Gould, J. (1865), Handbook to the Birds of Australia, the Author, London. McFarland, D.C. (1983), 'Ritualized aggression in the Eastern Spinebill Acanthorhynchus tenuirostris', Sunbird 13, 78-81. --(1986), 'The organization of a honeyeater community in an unpredictable environment', <lust. J. Ecol. 11, 1(]7-120. North, A.J. (1906), Nests and Eggs of Birds Found Breeding in Australia and Tasmania, Australian Museum, Sydney. Paton, D.C. (1980), 'The importance of manna, honeydew and lerp in the diets of honeyeaters', Emu 80, 213-226. --(1985) , 'Food supply, population structure, and behaviour of New Holland Honeyeaters Phylidonyris novaehollandiae in woodland near Horsham, Victoria', in Keast, A., Recher, H.F. , Ford, H. & Saunders, D. (Eds), Birds ofEucalypt Forests and Woodlands: Ecology, Conservation, Management, 219-230, Surrey Beatty, Sydney. Pyke, G. H. (1985) , 'The relationships between abundance of honeyeaters and their food resources in open forest areas near Sydney', in Keast, A. , Recher, H.F., Ford, H. & Saunders D. A. (Eds), Birds of Eucalypt Forests and Woodlands: Ecology, Conservation, Management, 65-77, Surrey Beatty, Sydney. Rooke, I. (1979) , The social behaviour of the honeyeater