I Australian Field Ornithology 2020, 37, 67–75 http://dx.doi.org/10.20938/afo37067075 Incubation behaviour and uniparental nestling care in the Huon Astrapia Astrapia rothschildi (Paradisaeidae) Richard H. Donaghey1, 2*, Donna J. Belder3 and Tony Baylis4 1Environmental Futures Research Institute, Griffith University, Nathan QLD 4111, Australia 280 Sawards Road, Myalla TAS 7325, Australia 3Fenner School of Environment and Society, The Australian National University, Canberra ACT 2601, Australia 4628 Utopia Road, Brooweena QLD 4621, Australia *Corresponding author. Email: [email protected] Abstract. The Huon Astrapia Astrapia rothschildi is endemic to the mountains of the Huon Peninsula, Papua New Guinea. We document, for the first time, the nest-site and height above the ground, incubation behaviour, nestling period, and uniparental care of the nestling (including brooding, feeding rate, nestling meals and nest hygiene) of the Huon Astrapia in the Yopno Urawa Som Conservation Area. Only the female incubated the single-egg clutch and provisioned the nestling. Incubation constancy was 67%. The nestling period was 25–27 days. Time spent brooding during the first week of the nestling period averaged 59%. The female provisioned the nestling at an average rate of 2.3 meals per hour. Of 32 nestling meals that could be identified, 81% were animal, predominantly insects, and 19% were fruit. Nearly all meals were regurgitated, and the female consumed most faecal sacs. We present four spectrograms: vocalisations of two females attending a nestling in their nests, and nestling calls. We compare incubation behaviour and uniparental nestling care of the Huon Astrapia with those in other birds-of-paradise, especially within the Astrapia clade. Introduction to mainland New Guinea, are sexually dimorphic in size and plumage: adult males are ~10% larger than females, The 41–43 species of birds-of-paradise (Paradisaeidae) and are predominantly black with an iridescent greenish- (Beehler & Pratt 2016; Gill & Donsker 2019) are renowned blue head; females are dull blackish brown with barred for their exquisite beauty and plumage, and their diversity underparts. of extraordinary courtship displays (Gilliard 1969; Cooper The Huon Astrapia Astrapia rothschildi is confined to & Forshaw 1977; Coates 1990; Frith & Frith 2009; Laman montane rainforest in the Finisterre, Saruwaged, Rawlinson, & Scholes 2012; Ligon et al. 2018). Males of the majority and Cromwell Mountains of the Huon Peninsula from of birds-of-paradise (35–37 species) are presumed to 1460–3500 m above sea level (asl) (Beehler & Pratt 2016); be promiscuous and polygynous, with females providing here it is the only species of Astrapia present. It forages for sole parental care (Frith & Beehler 1998; Frith & Frith arthropods and fruits in the middle-to-upper storeys of the 2009). By contrast, the four Manucodia species, the forest. Solitary displaying, dispersed males have a unique Trumpet Manucode Phonygammus keraudrenii, and the inverted courtship display (Frith & Beehler 1998; Laman & Paradise-crow Lycocorax pyrrhopterus are considered to Scholes 2012; Scholes et al. 2017). Thane Pratt (in Frith be monogamous with biparental care of offspring (Beehler & Beehler 1998) described an inverted courtship display in 1985; Frith & Beehler 1998; Frith & Frith 2009). The diets which a male slides below a horizontal perch, points his bill of adults and nestlings are important factors promoting the evolution of social systems such as mating system, male skywards and cocks his long fanned tail upward. Laman spatial dispersion and parental care in birds-of-paradise & Scholes (2012) described a courtship display in which (Beehler 1983; Beehler & Pruett-Jones 1983; Diamond the male hangs upside down, resumes an upright posture 1986; Frith & Beehler 1998). Male territorial dispersion for copulation and after copulation grasps the back of the in the presumed polygynous Brown Sicklebill Epimachus female, leans forward, and both male and female tumble meyeri correlated with a more insectivorous diet but a far down locked together. greater frugivorous diet favoured the evolution of true leks Very little is known about the breeding biology of the Huon in the Raggiana Bird-of-Paradise Paradisaea raggiana Astrapia. Two nests and an egg have been described (Frith (Beehler 1983; Beehler & Pruett-Jones 1983). In contrast, 1971; Frith & Beehler 1998) but neither the nest-site nor in a study at Mt Missim, the Trumpet Manucode specialised height of nest above the ground is known. The incubation in eating nutrient-poor, spatially and temporally patchy, and nestling periods, incubation behaviour, and parental rare figs (Moraceae), which promoted biparental care of care of the young are unknown. In this paper, we describe young, monogamy, and non-territorial dispersion (Beehler the nest-site and nest height, and document female 1985; Diamond 1986). incubation behaviour and parental care of the single young The phylogeny of birds-of-paradise by Irestedt et (including feeding rates, nestling diet, and nest sanitation) al. (2009) recognised five main clades, four of which at a nest in the Yopno Urawa Som Conservation Area represented the core birds-of-paradise. The five Astrapia (YUS CA), Huon Peninsula, Papua New Guinea (PNG). species are included in the fourth clade together with the We present spectrograms of vocalisations of the female two Paradigalla species and the two long-tailed Epimachus and nestling Huon Astrapia, and present photographs of sicklebills. The long-tailed Astrapia species, all endemic the nest-site, nest, and an adult female feeding a nestling. 68 Australian Field Ornithology R.H. Donaghey et al. Study site and methods At Nest 1 on 13 November, TB recorded the calls of a female that visited her nest and the calls of the nestling RHD and David Bryden conducted a 6-week exploratory using a DPA4060 omnidirectional microphone (placed trip that included the Huon Peninsula, during July– below the nest) with a long lead run to a Nagra LB August 2014, and selected the YUS CA as a study site recorder, with file type WAV 48 kHz/24bit during a session (Donaghey 2015a). Soon after, we flew into Sapmanga, lasting c. 86 minutes. He recorded the calls of a female YUS CA, elevation 900 m asl, arranged porters and guides returning to Nest 2 using a Sennheiser ME62 Cardiode at Gomdan village and walked up to Camp 12, elevation microphone (placed above the nest) with a short lead into 2300 m asl (06°01′S, 146°50′E), where we studied mid- an Olympus LS11 recorder, file type WAV 48 kHz/24bit. This mountain robins (Petroicidae) and opportunistically studied recorder was run for 65, 86 and 70 minutes on 9, 13 and other songbird species from 23 October to 6 December 20 November, respectively. Spectrograms were produced 2014 (Donaghey et al. 2019). While walking along a using Raven Pro 1.4 with FFT1024. trail uphill from Camp 12 on 25 October, we discovered Nest 1 of a Huon Astrapia when the incubating female flew The vegetation structure and plant families in a 1-ha from her nest. To determine her incubation behaviour, we plot of mid-montane rainforest 2400 m asl near Camp 12 erected a portable hide before 1200 h on 26 October, and were described by Inaho (2012). This upper-zone forest then RHD and DJB alternated 2-h nest-watches spanning plot was characterised by high stem density (mean of all daylight hours from 1200 h to 1800 h on 26 October and 25 stems/0.4 ha) and a tree height of mostly 10–20 m from 0600 h to 1200 h the following morning. dominated by one species (Platea excelsa) in the family We observed the female Huon Astrapia at the nest Icacinaceae. The other most important plant families are through a 25× telescope and timed the duration of all listed in Inaho (2012) and Donaghey et al. (2019). In this bouts on and off the nest to the nearest second with a plot, Inaho (2012) recorded 39 plant species in 36 genera lap/split stop-watch. An incubation session or ‘on-bout’ is and 28 families. During our stay at Camp 12 in October– the duration of time (minutes and seconds) spent by the December 2014, there was little sunshine, and heavy rain female on the nest during incubation. An absence or ‘off- fell most afternoons, evenings, and some mornings. bout’ is the time (minutes and seconds) that an incubating female spent away from the nest. In our study, incubation constancy is the percentage of a 12-hour day spent in Results incubation. In other studies of birds-of-paradise (discussed below), incubation constancy refers to the mean percentage Nest-site, nest, and nest dispersion of time that the female spent incubating during several nest-watches. While walking past the nest-site between Nest 1 (Figures 1–2), placed 5 m above the ground, was 27 October and 4 November, we opportunistically recorded whether the female was on the nest or foraging nearby. well-concealed in a tangle of epiphytic Freycinetia, a genus of mostly climbing plants (Pandanaceae), against the During a 1-hour afternoon nest-watch on 5 November, trunk (9 cm at breast height) of a slender understorey tree we observed the female visit the nest and deliver food, (9–10 m tall). The nest-tree was on a west-facing slope presumably to an unseen nestling. We assumed that at an altitude of 2470 m asl, and the nest had a southerly 5 November was Day 1 of the nestling period since on aspect. Nest 1, a substantial open cup of orchid stems, the afternoon of 4 November we saw the female return vines and rootlets, externally measured 215 mm in to her nest with no food in her bill. During the first week diameter and had a mean depth of 150 mm. We were of the nestling period, we observed Nest 1 on 5, 7 and unable to examine the interior nest materials or measure 11 November for a total of 9.5 hours.