Australian Field Ornithology 2019, 36, 24–30 http://dx.doi.org/10.20938/afo36024030 Nest, egg and parental care of a nestling in the New Guinean Lesser Ground-robin Amalocichla incerta Richard H. Donaghey1, 2*, Donna J. Belder3, Tony Baylis4 and Sue Gould5 1Environmental Futures Research Institute, Griffith University, Nathan 4111 QLD, 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 5269 Burraneer Road, Coomba Park NSW 2428, Australia *Corresponding author. Email: [email protected] Abstract. The Lesser Ground-robin Amalocichla incerta (Petroicidae) is endemic to mid-mountain forests in mainland New Guinea. Spectrograms of four songs are depicted. We describe the elevation and nest-site, height above the ground, structure and materials of three nests discovered in the Yopno Urawa Som Conservation Area, Huon Peninsula, Papua New Guinea, and compare these observations with two previously described nests. All three of the nests in the present study were 1.0–2.1 m above ground. The colour and dimensions of two eggs are described. At one nest with a feathered nestling estimated to be 13–16 days of age, a pair of adults disposed of faecal sacs and provisioned the nestling at a rate of 7.5 feeds per hour. The nestling period of 22 days was similar to that of two other montane New Guinean robins, but longer than that of most temperate and tropical Australian robins. Introduction Pratt 2016), and 1660–2420 m asl on the Huon Peninsula (Freeman et al. 2013). Its song, heard much more often The Lesser Ground-robin Amalocichla incerta (Petroicidae) than individuals are seen, is a light, breezy whistle of is a 30.7–32.5-g (mean 31.6 g, n = 2: Diamond 1972; several notes (Boles 2007). Pruett-Jones & Pruett-Jones 1982), shy and elusive Very little is known about the breeding biology of the ground-dwelling Australasian robin endemic to mid- Lesser Ground-robin. Two nests and one egg have been mountain forests in mainland New Guinea. It was named described (Pruett-Jones & Pruett-Jones 1982; Coates previously as the Lesser New Guinea Thrush and assigned 1990). Pruett-Jones & Pruett-Jones (1982) described to the thrush family Turdidae or subfamily Turdinae in the nestling plumage at 11 days of age and on the day of Old World Flycatchers (Muscicapidae) (Mayr 1941; Ripley hatching. Incubation behaviour and parental care of the 1964; Rand & Gilliard 1967; Diamond 1972). Beehler & young have never been quantified and the roles of the Finch (1985) treated Amalocichla as Australasian robins male and female in incubation and parental care activities based on the DNA–DNA hybridisation study by Sibley & are unknown. We here document the dimensions of three Ahlquist (1982) that found the similar ground-dwelling nests found in the Yopno Urawa Som Conservation Area Australo-Papuan scrub-robins Drymodes were most (YUS CA, named after the Yopno, Urawa and Som Rivers), closely related to the Australian robin genera Eopsaltria Huon Peninsula, PNG, and present new data on nest-site and Heteromyias and distant from the Turdus thrushes. and height of the nest above the ground. We also document The molecular analysis by Norman et al. (2009) placed the colour and size of the egg, clutch-size, parental care Amalocichla within the Petroicidae but did not support a of a nestling, and nestling growth and development. We sister relationship between Amalocichla and Drymodes. present spectrograms of four different songs of the Lesser Phylogenetic analyses by Christidis et al. (2011) of all Ground-robin and photographs of the nest-site, nest, egg, Australasian robin genera identified six lineages, with an incubating adult on the nest, and a nestling. Amalocichla forming a separate lineage Amalocichlinae not related to Drymodes. Amalocichla is a sister lineage to the New Guinean Pachycephalopsis (Christidis et al. 2011; Study site and methods Beehler & Pratt 2016). The 14–15-cm Lesser Ground-robin is sexually RHD and David Bryden conducted a 6-week exploratory monomorphic, has a brown head, rufous-brown upperparts, trip in the Adelbert Mountains, Huon Peninsula, and brownish-buff underparts but with the belly whiter with around Tari in July–August 2014 to find a suitable site to more-rufous markings, long slender grey legs, a short tail, study robins (Donaghey 2015a). We found four species of and a diagnostic whitish forehead-band and throat (Coates mid-mountain robins in the remote intact forest of the YUS 1990). Of the two subspecies recognised by Beehler & CA, Huon Peninsula, so RHD selected Camp 12 as a base Pratt (2016), brevicauda occurs on the Huon Peninsula, camp there (for further details see Donaghey et al. 2019). Papua New Guinea (PNG), where we conducted our study. TB, DJB and RHD stayed at Camp 12 (elevation 2300 m The Lesser Ground-robin forages for arthropods on the asl; 06°01′S, 146°50′E) from 23 October to 6 December forest floor at altitudes of 1200–2750 m above sea-level 2014. One of our guides, Liberth Wesley, discovered Lesser (asl), mainly 1750–2500 m asl (Coates 1990; Beehler & Ground-robin Nest 1 with a nestling on the afternoon of Breeding biology of New Guinean Lesser Ground-robin 25 30 October. We visited the nest-site (elevation 2411 m asl), Observations with him at 1430 h on 31 October and photographed the nest and feathered nestling. The nestling was weighed Song with a digital electronic balance to the nearest 0.1 g (and Spectrograms of four different songs of the Lesser Ground- again on 5 and 11 November) and the lengths of its wings robin (Figure 1) show that the whistled notes of the songs and tail measured to the nearest millimetre with a metal range in frequency from ~2 to 3.5 kHz and the duration ruler and the head–bill and tarsus lengths measured with of each song is c. 2 seconds. Two songs (2 and 4: see callipers to the nearest millimetre. From a bush-hide built Figure 1) start with two notes of a low pitch, rise to a ~10 m from the nest by two of our guides, DJB and RHD higher pitch and then four notes cascade to a lower pitch. conducted two 2-hour nest-watches (4 h/morning) between These two songs resemble the pattern described by Pratt 0700 and 1100 h on 2, 3 and 5 November, for a total of 12 & Beehler (2015, p. 487) as “a beautiful tune of usually h, to determine the number and rate of feeding trips, nest 6–7 clear piping notes” that “jump around in pitch and sanitation, and comfort movements of the nestling. usually end on a low note”. TB returned to the YUS CA with SG from 6 October to 17 November 2017 to record bird vocalisations. They established a base camp at Camp Astrapia (2009 m asl; Nest-site, nest and egg 06°01′S, 146°49′E). For two Lesser Ground-robin nests (Nests 2 and 3, each with a single egg), they described Nest 1, found in 2014, was 2.1 m above ground in a the nest-site, and recorded the altitude, height of nest 4–5-m-tall, densely foliaged, slender understorey tree. above the ground and dimensions of the nest and egg, and It was built on a horizontal branch 46 cm from the trunk photographed the nest-site, nest, and egg. TB recorded of the nest-tree and 99 cm from the outermost foliage four different songs of Lesser Ground-robins with a Nagra (Figures 2–3). The nest-tree was on a hill slope 2411 m LB and used file type WAV 48 kHz/24bit to prepare the asl, and the nest had a southerly aspect. Nest 2, found spectrograms using Raven Pro 1.4, Hann window with in 2017, was built in the fork of a Coffee Coffea arabica FFT1024. All recordings were lodged both at the British shrub and attached to the stem of a vine. It was built 1.2 m Library of Wildlife Sound, UK, and the Macaulay Library, above the ground, with an easterly aspect, at an altitude of Cornell Lab of Ornithology, USA. 1988 m asl (Figures 4–5). The foliage of a nearby tree provided cover and shade above the Coffee shrub and Tropical rainforest plants could not all be identified (from the nest. Nest 3, also found in 2017, was placed 1.0 m fruit and flowers) in the short time available to us at our above the ground, on the side of a tree-trunk with a dense study sites but they have been described for a 1-ha plot covering of moss, at an altitude of 1790 m asl, and thus 2400 m asl <200 m upslope from Camp 12 (Inaho 2012; was well camouflaged. see also Donaghey et al. 2019). Inaho (2012) recorded 39 plant species in 36 genera and 28 families, but this All three open-cup-shaped nests in this study were species richness was low compared with lower elevations. composed externally of bright-green moss, with the inner He did not describe the vegetation at Camp Astrapia. egg-cup lined with fine blackish rootlets (Figures 3–5). The During our stays at Camp 12 in October–December 2014 bulkier Nest 1 had some dead leaves (20 cm long) and and Camp Astrapia in October–November 2017, there dried fern-frond pieces (10–23 cm long) on the exterior was little sunshine, and heavy rain fell most afternoons, (Figure 3). Variation in the size of the nests is shown in evenings and some mornings.