VOL. 11 (1 ) MARCH 1985

AUSTRALIAN WATCHER 1985, 11 , 1-6

Notes on the Ecology and Breeding Biology of the Golden-headed Cisticola Cisticola exilis

By DAVID C. McFARLAND, Department of Zoology, University of

New England, Armidale, N .S.W. 2351

Summary Golden-headed Cisticolas Cistico/a exilis were obsetved in a mixed scrub and grassland habitat near Sydney, N.S.W. over two years. Tall grass made up most of the habitat used by the , with the scattered shrubs being important as nest sites. Densities ranged from 3.5 birds/ha in the non-breeding season to 6.5 birds/ha in the breeding season. Breeding occurred between October and February, with the overall reproductive success of the population being 32.1% (eggs to fledgelings). ·

Introduction Over a two-year period, observations were made of a number of bird species inhabiting the open forest and scrub-grassland habitats in Beverly Hills, Sydney (McFarland 1984 a,b). One of the most conspicuous species present in the scrub-grassland was the Golden-headed Cisticola Cisticola exilis. The following paper presents the results concerning the ecology (bird densities and habitat composition) and breeding biology (timetable of breeding activities and breeding success) of this species. The timing and duration ofbr~eding seasons of the Golden-headed Cisticola in Australasia is also examined and discussed.

Study area and methods Cisticolas were studied in a three-hectare plot in Beverly Hills, New South Wales. The plot was bordered by a golf course, playing fields and Wolli Creek. Tall grass (10 - 60 em high) dominated the vegetation, with some scattered clumps of tea-tree Leptospermum juniperinum and Blackberry Bramble Rubus vulgaris. Short grass (less than 10 em high) was present along the edges of the plot and beside the tracks while bulrushes sp. were common in the creek. Between January 1978 and January 1980 I made regular visits to the plot each month. Total observation time was 37 hours (1.5 ± 0.7 hr/month, mean ± standard deviation). During each visit all Cisticolas seen were counted and their positions (where first seen) marked on a gridded map. As no individuals were banded, birds were recorded as male, female or immature. In the non­ breeding season no differentiation between sexes or age classes could be made. Double counting of birds during a visit was unlikely since the birds, even when flushed repeatedly, never moved very far. Notes were also kept of the activities (calling and displaying) and condition (plumage) of adult birds, as well as the position of any nests and their contents. AUSTRALIAN 2 McFARLAND BIRD WATCHER

Results Ecology Cisticolas were found to be using only 1.7 ha of the plot The birds were rarely recorded in the thick clumps of Leptospermum and I never saw them in areas of short grass. Over half (53.6%) of the 1.7 ha used was tall grass with Leptospermum bushes occupying 18.6% of the area. Short grass (9.3%), bare ground (9.3%), bulrushes (6.9%) and brambles (2.3%) made up the remainder of the area. For most of the non-breeding periods six to eight birds were present in the 1.7 ha area, giving a density of3.5- 4.7 birds/ha. In the breeding season, when free-flying young were present, the peak density of 6.5 birds/ha was recorded. The seasonal changes in the total Cisticola numbers in the plot are shown in Figure 1. Since only three males were present for most of the time an estimate of home range size would be 0.57 ha/ male, assuming equal range sizes for each male. The males appeared to hold territories, at least in the breeding season, since the males were always found in certain areas. On eight occasions I saw two males perch close to (< 5 m) and face each other, give a number of scolding calls for a few minutes, and then move off in opposite directions. Only one female was ever found in the same area as each male but I do not know whether they range freely across territories or not During the study only six interactions (all chases) between conspecifics were noted. All involved males as the aggressors and they took place in the breeding season (male- male= 3, male- female= 2, male- immature= 1). Twice, adult male Cisticolas were seen chasing female Superb Fairy-wrens Malurus cyaneus that were in the vicinity of Cisticola nests.

12

10 .. 8 0 a.. 6 ...... "C"'.... 4 al 0 z 2

0 J A A D J A A D J 78 79 80 Months

Figure l. Abundance of Golden-headed Cisticolas in the plot (1978-1980). VOL. 11 (1) MARCH 1985 Ecology and Breeding of Golden-headed Cisticola 3

Golden-headed Cisticola Cisticola exilis. Plate 2 Photo: Beryl & Keith Richards

Breeding biology For the timetabling of the following breeding activities see Table 1. Breeding activit)' began in July when male Cisticolas started moulting into their breeding plumage (see Pizzey 1980 for descriptions of the various plumage phases), and giving loud calls (usually a sound like 'mizt - thrit'). However it was not until October that the distinctive display flights of the males were observed (for a description of the display see Gwynne 1955). The first nests with eggs were found in October. Of the 10 nests located during the study six were in tall grass under Leptospermum bushes and the remaining four were in brambles. Only those in brambles had live leaves stitched into the outer shell of the nest. No nest was higher than 20 em or lower than 5 em above the ground. Clutch size was either three (n = 2 nests) or four (n = 6 nests) eggs. Apart from the 10 nests actually discovered, an additional five nests were assumed to exist due to the presence of fledgelings with adults in areas where no nests had been found. The last active nests (i.e. eggs or chicks present) were recorded in February, but immature birds were seen in the study area up to mid April. Once nesting was finished, all calling and displaying by the males ceased. By the end of March all males had moulted into their eclipse plumage. Breeding success, in terms of the average number of fledgelings recorded per nesting attempt, is given in Table 2. The high value in 1977-78 was a result AUSTRALIAN 4 McFARLAND BIRD WATCHER of the study starting late in the breeding season and only two nests were found. In 1979-80 the low value was due to grass fires which destroyed two nests and reduced the feeding area and the potential number of nesting sites for pair I. Assuming that the average clutch size was 3.75 eggs then, over the study period, approximately 56 eggs were laid of which only 18 survived to become fledgelings. This gives an overall survivorship (eggs to fledgelings) of 32.1%. The real reproductive success was probably lower than this since I did not find all the nests with eggs or young.

Discussion Golden-headed Cisticolas are usually found in stunted heath with tall grass, shallow swamps and occasionally crops (Gwynne 1955). This preference for tall grass was evident among the birds in this study, with over half the habitat used being tall grass (including the bulrushes). Even though Leptospermum bushes and brambles made up only a small proportion of the habitat they were important vegetation components since they appeared to be favoured as nest sites. Cisticolas will nest in tussock grasses when shrubs are absent (Givens 1926) but will prefer shrubs, such as brambles, whenever available (Gibson & Sefton 1953). Estimates of density of the Golden-headed Cisticola vary considerably [New Guinea: savanna = 0.8 (Bell 1982); Australia: grassland = 20.0 - 26.7 (Hall 1974); swamp = 1.2 (Blakers et al. 1984); tussock grass = 2.0 (Givens 1926); scrub-grassland = 6.5 (this study); all values are birds/ha]. All the figures except Hall (1974) were for breeding populations. The fact that Cisticolas form loose aggregations in the non-breeding season (Hindwood 1966; Hall 1974) would account for the high densities recorded. The variability among the other estimates could reflect differences in habitat carrying capacity (differences in the availability of food and nest sites), or they could be due to differences in the methods used by the authors in measuring densities. In the Beverly Hills population, males moult into breeding plumage in August. This is similar to that recorded by Hindwood (1966) but a month earlier than that noted by Gwynne (1955). The plumage change and the singing are thought to attract females and advertise territories, while the flight display is considered to stimulate the female, attract her to the nest and draw attention away from her activities (Hindwood 1966; McGill 1970). A more detailed study of these aspects of the birds' behaviour is required. During the study I found no evidence of polygyny as claimed by Hindwood (1966). Just as Hindwood & McGill (1958) recorded, the males in this study moulted into eclipse plumage in the March-April period. Compared to other Australian , the reproductive success of the Golden-headed Cisticolas in Beverly Hills (32.1%) is similar to that of the Eastern Yellow Robin Eopsaltria australis (28%: Marchant 1984), but well below the values for eith.er the Willie Wagtail Rhipidura leucophrys (58%: Marchant 1984) or the Welcome Hirundo neoxena (53%: Marchant & Fullagar 1983). While weather may influence the breeding success of Cisticolas (Gibson & Sefton 1953), for my population the most likely factor was predation. Domestic cats Felis catus, Australian Kestrels Falco cenchroides and Black-shouldered Kites Elanus notatus were all regular visitors to the plot. VOL. 11 (1) MARCH 1985 Ecology and Breeding of Golden-headed Cisticola 5

Table 1

Summary of the breeding activities of the Golden-headed Cisticola (+ indicates recorded in that month; ++ recorded in both years; both years' data combined)

Activities Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

Breeding plumage ++ ++ + + ++ ++ ++ ++ ++ Male calling ++ ++ + + ++ ++ ++ ++ Male displaying ++ ++ ++ ++ ++ Active nest* ++ + ++ ++ ++ Immatures present + ++ ++ + +

*eggs or chicks present.

Table 2

Total number of fledgelings produced by each pair of Golden-headed Cisticolas and the mean reproductive success for all birds combined as the mean number of fledgelings produced per nest built (n = number of nests found or inferred for each pair in each season) Pair 1977-78 (n) 1978-79 (n) 1979-80 (n)

I 1 (1) 3 (3) 0 (2) II 3 (1) 4 (3) 2 (2) III 2 (1) IV 3 (2) Mean 2.0 1.3 0.8

- not recorded in the study area.

Table 3

The duration and timing of breeding in the Golden-headed Cisticola (moving from north to south; number of breeding months in parentheses)

Months Location Reference

Dec-Mar (4) New Guinea Bell (1982) Dec-Apr (5) North Queensland Ey (1977) Dec-Mar (4) Northern Territory Storr (1977) Jan-Mar (3) Na_tural bush } northern Serventy & Oct-Mar (6) Imgated area Western Australia Whittell (1976) Aug-Apr (all year Tropics Beruldsen (1980) in wetter areas) Sept-Mar (7) New South Wales Morris et al. (1981) Sept-Mar (7) N.S.W. (Sydney) Hindwood & McGill (1958) Oct-Feb (5) N.S.W. (Sydney) This study Nov-Mar (5) AC.T. (Canberra) COG (1971) Oct-Dec (3) Tasmania Littler (191 0) AUSTRALIAN 6 McFARLAND BIRD WATCHER

The duration and timing of breeding (i.e. when birds actually nesting) recorded in this study is similar to that noted for the Golden-headed Cisticola elsewhere in New South Wales (Table 3). Table 3 also provides the breeding seasons for this species in all parts of Australia plus one record from New Guinea. The conspicuous feature of the results is the latitudinal change in both the duration and timing of breeding. [While this feature has been noted previously (e.g. Beruldsen 1980), I do not know of any paper where the data have been fully presented.] In the northern and southern areas breeding lasts three to five months, with that in the north starting one to two months later than in the south. The longest seasons are found in New South Wales (up to seven months). The only exceptions to this trend are northern areas which are wet for all or most of the year, e.g. irrigated land (Serventy & Whittell 1976; Beruldsen 1980). These areas have the longest seasons (up to nine months) but could be considered unnatural since such areas are mostly man-made. It appears that the length and initiation of a breeding season is determined by the climate (rainfall and temperature). This determines the period of favourable plant growth and hence the time of increased availability of nest sites, nesting materials and insects.

Acknowledgements I would like to record my thanks to the late Harry Bell for his helpful remarks on an earlier draft of this paper.

References Bell, H.L. (1982), 'Abundance and seasonality of the savanna avifauna at Port Moresby, Papua New Guinea', Ibis 124, 252-274. Beruldsen, G. (1980), A Field Guide to the Nests and Eggs ofAustralian Birds, Rigby, Adelaide. Blakers, M., Davies, S.J.J.F. & Reilly, P.N. (1984), Th e Atlas of Australian Birds, Melbourne University Press, Melbourne. Canberra Ornithologists Group (1971), A Field-list to the Birds of Canberra and District, Pirie Printers, Fyshwick. Ey, A (1977), 'Notes on the Streaked Grass-Warbler', Sunbird 8, 20-21. Gibson, J.D. & Sefton, A (1953), 'Notes on the desertion of nests by Fantail-Warblers', Emu 53, 74-77. Givens, T.V. (1926), 'Days among the Corn-Birds', Emu 26, 56-58. Gywnne, AJ. (1955), The Golden-headed Fantail Warbler', Gould League Notes 21 , 13-14. Hall, B.P. (1974), Birds of the Harold Hall Australian Expeditions 1962-70, Trustees British Museum, London. Hindwood, K.A (1966), Australian Birds in Colour, Reed, Sydney. ~~ & McGill, AR. (1958), The Birds of Sydney, Royal Zoological Society of N.S.W., Sydney. Littler, F.M. (1910), A Handbook of Birds of Tasmania, Littler, Launceston. Marchant, S. (1974), 'Analysis of nest-records of the Willie Wagtail', Emu 74, 149-160. -- (1984), 'Nest-records of the Eastern Yellow Robin Eopsaltria australis', Emu 84, 167- 174. -- & Fullagar, P.J. (1983), 'Nest records of the Welcome Swallow', Emu 83, 66-74. McFarland, D.C. (1984a), 'Protection behaviours of breeding White-plumed Honeyeaters Lichenostomus penicillatus', Emu 84, 42-43. -- (1984b), 'The breeding biology of the Willie Wagtail Rhipidura leucophrys in a suburban woodlot', Corella 8, 77-82. McGill, AR. (1970), Australian Warblers, Bird Observers Club, Melbourne. Morris, A.K., McGill, AR. & Holmes, G. (1981), Handlist of Birds in New South Wales, N.S.W. Field Ornithologists Club, Sydney. Serventy, D.L. & Whittell, H.M. (1976), Birds of Western Australia, University of Western Australia Press, Perth. Storr. G.M. (1977), Birds of the Northern Territory. Western Australia Museum, Perth . •