Amytornis 19 WESTER A USTRALIA J OURAL OF O RITHOLOGY Volume 3 (2011) 19-29 ARTICLE Observations on the foraging ecology of honeyeaters (Meliphagidae) at Dryandra Woodland, Western Australia Harry F. Recher 1, 2, 3* and William E. Davis Jr. 4 1 School of Natural Sciences, Edith Cowan University, Joondalup, Western Australia, Australia 6027 2 The Australian Museum, 6-8 College Street, Sydney, New South Wales, Australia 2000 3 Current address; P.O. Box 154, Brooklyn, New South Wales, Australia 2083 4 Boston University, 23 Knollwood Drive, East Falmouth, MA 02536, USA * Corresponding author. Email: [email protected] Abstract. Dryandra Woodland, a Class A conservation reserve, on the western edge of the Western Australian wheatbelt lacks the large congregations of nectar-feeding birds associated with eucalypt woodlands to the north and east of the wheatbelt. Reasons for this are not clear, but the most productive woodlands (Wandoo Eucalyptus wandoo ) at Dryandra are dominated by Yellow-plumed Honeyeaters ( Lichenostomus ornatus ), which exclude smaller honeyeaters from their colonies. There is also comparatively little eucalypt blossom available to nectar- feeders during winter and spring when we conducted our research at Dryandra. During winter and spring, honey- eaters are dependent on small areas of shrublands dominated by species of Dryandra (Proteaceae), with species segregated by size; the smaller species making greater use of the small inflorescences of D. sessilis and D. ar- mata , while the large wattlebirds used the large inflorescences of D. nobilis . Honeyeaters at Dryandra also use other energy-rich sources of carbohydrates, such as lerp and honeydew, and take arthropods, segregating by habi- tat, foraging behaviour, and substrate. The importance of Dryandra within Dryandra Woodland is particularly relevant to fire management. If Dryandra shrublands are burnt for fire management without ensuring adequate numbers of mature Dryandra plants are retained in the reserve, the nectar available to nectar-feeders could be re- duced to levels at which some species could not be sustained within the reserve. Given the extensive land-clearing in the wheatbelt, this could adversely affect species survival in a regional context and affect the pollination of na- tive plants. Keywords . Honeyeaters, Meliphagidae, eucalypt woodlands, Dryandra , nectar-feeding, Western Australia. Introduction (Recher and Abbott 1970; Ford and Paton 1976; Ford 1977; Pyke 1980). Many honeyeaters depend on flowering plants for nec- Honeyeaters are dispersive species reliant on a se- tar throughout the year, and rely on a range of plant quence of nectar resources that differ in their spatial species that flower at different times of the year and and temporal availability (Keast 1968; Ford 1977; Ford have different floral characteristics (Keast 1968; Ford and Paton 1977; Halse 1978; Pyke 1980). Identifying 1977; Ford and Paton 1977; Halse 1978; Pyke 1980). nectar and other food resources in major habitat types Other species use alternative carbohydrates (sap, hon- is necessary to ensure that conservation of honeyeaters eydew, lerp, and manna) as their principal sources of occurs on spatial and temporal scales large enough to energy (Paton 1980; Woinarski 1984; Loyn 1985; Re- accommodate the requirements of the birds. Without cher et al. 1985). All honeyeaters require arthropods integrated landscape management, the risk is that the for protein, especially during moult and when breeding incremental loss of even small nectar resources in the sequence will cause the progressive decline of honey- eaters, regardless of the amount of nectar available at other times or locations (Recher 1999; Ford et al. A Publication of: 2001; H. A. Ford personal communication). Birds Australia Dryandra Woodland is one of the largest remaining Western Australia areas of natural vegetation in the Western Australian Wheatbelt and is notable for its comparatively intact ISSN 1832-3482 20 Recher and Davis. Foraging behaviour of honeyeaters at Dryandra Woodland biota. Dryandra Woodland has a rich honeyeater avi- Shrubland plots ranged in size from 2.2 to 10.1 ha fauna, but the Wandoo ( Eucalyptus wandoo ) and Pow- (Table 1). Only Dryandra sessilis occurred on Sessilis. derbark Wandoo ( E. accedens ) woodlands characteris- Dryandra sessilis was absent from Firetower, but D. tic of Dryandra are dominated by Yellow-plumed sessilis , D. nobilis , and D. armata were present on Honeyeaters ( Lichenostomus ornatus ), a colonial spe- Malleefowl, Dry Ridge, and Possum (Table 1). Sessilis cies, which excludes smaller birds from their colonies was divided by a narrow (<2.5 m wide) dirt road and (Recher and Davis 1998; Wilson and Recher 2001; occurred on deep sandy soil at mid-slope where it was Recher and Davis unpublished data). This contrasts flat. The other plots were along ridges on lateritic soils with the eucalypt woodlands to the north and east of adjacent to narrow roads. the wheatbelt where nectar-feeders are abundant WED recorded honeyeater foraging and estimated (Chapman and Kealley 2001; Recher and Davis 2002, nectar abundance between 1 July and 7 October 1997. 2010, unpublished data) and there are extensive wood- In November 1997, the density (no./m 2) of each Dry- lands, with abundant nectar, that are not dominated by andra species on the shrubland plots was measured. Yellow-plumed Honeyeaters. HFR censused the shrubland plots, recorded honey- An objective of our work in Western Australia is to eater foraging and estimated floral abundance between compare bird assemblages, including nectar-feeders, of May 1998 and August 1999. HFR also recorded honey- different eucalypt woodlands. We therefore extended eater foraging behaviour in wandoo woodlands at Dry- our studies at Dryandra to include shrublands where andra between 1996 and 2004. nectar-feeders congregated. In addition, we continued Dryandra Woodland is subject to annual fuel reduc- to work in wandoo woodlands to increase our observa- tion burning. At the time the study was initiated, all tions of species for which we had limited data (see Re- plots had been unburnt for more than ten years. Shortly cher and Davis 1998). The study reported here comple- after HFR commenced counts in May 1998, Dry Ridge ments our earlier research, concentrating on areas of was burnt, while Sessilis was burnt after counts in Au- high nectar production, and focusing on honeyeaters. gust 1999, both as part of fuel reduction burns. After Our aims were to determine what honeyeaters were burning, work on both plots ended, because no dryan- present at Dryandra Woodland during winter and dras were flowering. spring, what nectar resources were available, and tem- poral patterns of nectar availability and use. In addi- Floristics and flower abundance tion, we summarize the foraging ecology of honey- The area and density of bird-pollinated species in eaters in wandoo woodlands, adding data collected shrubland plots were measured in November 1997. from 1996 to 2004 to that previously published Transects through the plots were positioned centrally (Recher and Davis 1998). Our objective was to contrib- along the long axis and 10 x 10 m quadrats randomly ute to a comprehensive account of the foraging ecology located along the transects. On Sessilis, quadrats were of honeyeaters at Dryandra, with the aim of assisting in 10 x 10 m and 5 x 5 m (because of narrowing of the the conservation and management of Dryandra’s avi- stand), with the larger quadrats divided by four for cal- fauna and of honeyeaters in southwestern Western culations of average plant density. The number of Australia. quadrats differed between plots, but a minimum of 5% of the patch was sampled if less than 2 ha; 2.5% be- Methods tween 2 and 5 ha; and, 1.25% if the patch was greater Study area than 5 ha. For some small stands, all plants were Dryandra Woodland is a Class A Conservation Reserve counted. Mean density of each species of Dryandra (centred on 32°45’S, 116°55’E) near the town of Nar- was calculated using the average number of plants per rogin 180 km southeast of Perth, Western Australia. quadrat and the total area of the plot. The height of Plots were chosen for an abundance of nectar-rich each plant within the sampling quadrats was measured flowers, ease of access, and proximity to the wandoo to the nearest 0.25 m and used to calculate average woodlands studied by Recher and Davis (1998). The heights. shrublands (Dry Ridge, Fire Tower, Malleefowl, Pos- WED estimated the number of inflorescences for sum, and Sessilis) were dominated by one or more spe- each species of Dryandra between 15 July and 7 Au- cies of Dryandra (D. nobilis , D. sessilis , and D. ar- gust 1997 by counting the inflorescences on 10 ran- mata ). Dryandra nobilis is a tall shrub (to 3 m in domly selected plants of each species on each of the height), with large inflorescences (8-22 cm long by 5- shrubland plots. When WED scored inflorescences on 22 cm wide) on sturdy branches. Dryandra sessilis is Dry Ridge and Possum, D. armata was not in bloom. also tall (to 6 m), but has smaller inflorescences and The number of inflorescences for D. armata was there- less sturdy branches. Dryandra armata is a generally a fore estimated from the average number per plant on low shrub (<1 m), but can grow to 3 m. Dryandra ar- Firetower and Malleefowl. mata had the smallest inflorescences and least sturdy Using the density of plants, size of patches of each branches. species within a plot, and the mean number of inflores- Amytornis 3 (2011) 19-29 Recher and Davis. Foraging behaviour of honeyeaters at Dryandra Woodland 21 Table 1. Patch area and mean Dryandra species density, height, and number of inflorescences per plant, with an estimated total number of inflorescences/species for five shrubland plots in Dryandra Woodland during July/August 1997. Species den- sity and heights differed among mono-specific stands within each patch; the range of densities and heights are given.