Australian Field Ornithology 2020, 37, 56–58 http://dx.doi.org/10.20938/afo37056058

An overlooked first nest of the Malaita Monarch malaitae

Vladislav Marcuk1* and Donovan de Boer2

1Justus Liebig University Schanzenstraße 12, 35390 Giessen, Germany 2Berliner Straße 135, 15569 Woltersdorf, Germany *Corresponding author. Email: [email protected]

Abstract. The Malaita Monarch Symposiachrus malaitae, formerly considered to be a subspecies of the S. barbatus, is native only to Malaita Island in the eastern Solomon Islands. The natural history of this globally near-threatened endemic remains virtually unknown; this includes basic aspects of the breeding biology, including the description of the nest and eggs. Here we provide a first description of the nest, based on a specimen in the American Museum of Natural History and compare the nest structure, characteristics and composition with the nest of the Solomons Monarch.

Introduction

The poorly known lineage of pied monarchs Symposiachrus spp. compromises 19 distinct members of the family Monarchidae, with the majority of proximal taxa geographically confined to the Lesser Sundas of Indonesia and the Solomon Islands. Historically allied with the genus , a comparative phylogenetic analysis, investigating the systematic affinities of the core monarchs, indicates a rapid diversification within the multi- genera core clade and supports several monophyletic and paraphyletic lineages (Filardi & Smith 2005). In addition, morphological and phonological variation within the insular forms of the pied monarchs provides further evidence of rapid radiation (Filardi & Smith 2005; del Hoyo et al. Figure 1. Left, Malaita Monarch; right, Solomons Monarch; 2016). These investigations resulted in the re-evaluation of after Mayr (1931), Dutson (2011) and del Hoyo et al. (2019). subspecies taxonomic status and the elevation of several Illustration: Vladislav Marcuk to distinct species rank (Filardi & Smith 2005; del Hoyo & Collar 2016). Hitherto the Malaita Monarch was treated as conspecific Methods, results and discussion with the Solomons Monarch Symposiachrus barbatus. However, both species show evident divergence in their Herein we provide a first description of the nest based morphological appearance. As well as the slightly larger on a single specimen in the American Museum of average size of the Malaita Monarch, the following Natural History (AMNH, catalogue number EN 15565). plumage characteristics distinguish it from the Solomons The nest was collected on Malaita in May 1930 by Monarch (see Figure 1): (1) isolated moustache-patch and W. F. Coultas during the Whitney South Sea Expedition. side-collar, with black breast extending to carpal joints in No further details are given on the original label regarding the Malaita Monarch (compared with smaller black breast- nest content, collecting locality or parental behaviour. patch that does not separate the white lower breast from Presumably the nest was abandoned or not active. No the moustache-patch and side-collar), (2) shiny white evidence of the species identity is provided on the original scalloping within the lower breast-patch only in the Malaita label, but Coultas collected several specimens of the Monarch, and (3) white outer rectrices with bluish-black tips species (AMNH specimen records/database: see Mayr and bluish-black central rectrices in the Malaita Monarch 1931), and presumably observed close to the nest or (compared with black rectrices, the outer three of which other active nests during his fieldwork. Based on the nest are white-tipped, in the Solomons Monarch). morphology and its collection history, we do not doubt the species to which this nest belongs. The Malaita Monarch forms a monotypic, globally near- threatened species endemic only to the main island of The nest is a deep, rigid cup, typical of the genus. The Malaita in the eastern Solomon Islands (Mayr 1931; absence of lateral and ventral attachments indicate that it BirdLife International 2020). Information about the ecology was likely situated in a small, horizontal fork. The inner cup and population of the species is very limited, with the is mostly of fine vegetable fibres (1–2 mm thick) that are breeding biology virtually unknown (del Hoyo et al. 2019). firmly interwoven with the outer layer. Externally, the nest Malaita Monarch: Description of overlooked first nest 57

Figure 2. Nest of the Malaita Monarch in the AMNH (catalogue number EN 15565): (a) view from above, with scale bar, (b) view from the side. Photos: Bentley , AMNH

is composed of a mat (>5 mm thick) of green bryophytes, of this cup-shaped nest was of thin plant fibres, lined with without any evident presence of ornamentations. The spider webs and the internal cup was mostly composed external diameter is 88.67 mm (at the widest point), internal of fine to thick aerial roots (Dahl 1899). It contained two diameter 57.85 mm, height of the nest 63.43 mm, and the pale-pinkish eggs with dark-red spots, and had an external thickness of the nest wall 5.47–12.66 mm (measured with diameter of 75 mm, height of 80 mm, inner cup diameter of a digital caliper: B. Bird pers. comm.). 47.5 mm and cup depth of 40 mm (Dahl 1899). The nest bears a resemblance to the structure and composition of the nest description by Schodde (1977) for Acknowledgements the closely related Solomons Monarch and by Dahl (1899) for the Black-tailed Monarch S. verticalis. To date, only We thank the American Museum of Natural History and staff for allowing us to use the material and data for this note. We are two nests of the Solomons Monarch have been described grateful to Paul Sweet and Brian Smith for helping us with the (Rothschild & Hartert 1901; Schodde 1977; Coates 1990). initial request. We particularly acknowledge the assistance of The first was located on 27 April 1901 in a fork of a branch Bentley Bird, who generously helped us and provided the nest and contained a single egg (21.5 × 15.5 mm). This nest measurements and photographs. We thank Clifford B. Frith, was mainly of dry grass and ‘human hair’, with cobwebs Guy Dutson, Julia Hurley and Phil Gregory for suggestions and and white spider-nests externally; dry leaves were attached comments that significantly improved the manuscript. to the nest base. The second nest was discovered on 7 August 1964 in montane primary forest 1100 m above sea level (Schodde 1977). It contained two eggs References (averaging 22.5 × 17.5 mm) and was placed ~1 m above BirdLife International (2020). Species factsheet: Symposiachrus the ground in a fork of a sapling). It is described as a malaitae. Available online: http://www.birdlife.org (retrieved robust, cup-shaped structure composed predominantly of 20 March 2020). vegetable fibres interwoven with a thick layer of bryophytes Coates, B.J. (1990). The Birds of Papua New Guinea, Including forming the outside layer (Schodde 1977). It had an external the Bismarck Archipelago and Bougainville, Volume 2: diameter of 75 mm, height of 100 mm, inner cup diameter . Dove Publications, Brisbane. of 45 mm, and a cup depth of 55 mm (Schodde 1977). Dahl, F. (1899). Das Leben der Vögel auf den Bismarckinseln According to the local people, two eggs form the clutch Mitteilungen aus dem Museum für Naturkunde in Berlin. (Schodde 1977). The clutch-size of the Malaita Monarch Zoologisches Museum und Institut für Spezielle Zoologie (Berlin) 1 (3), 107–223. remains undocumented but is unlikely to differ from that of del Hoyo, J., Collar, N.J. & Christie, D.A. (2019). Malaita Monarch the Solomons Monarch (1–2 eggs). The base colour of the (Symposiachrus malaitae). In: del Hoyo, J., Elliott, A., Sargatal, eggs of the Solomons Monarch is cream-white, and red- J., Christie, D.A. & de Juana, E. (Eds). Handbook of the Birds brown spots and blotches are concentrated at the larger of the World Alive. Lynx Edicions, Barcelona, Spain. Available egg pole, where they form an irregular zone (Rothschild & online: https://www.hbw.com/node/1343824 (retrieved Hartert 1901). 12 October 2019). del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., The presumed nest of the Black-tailed Monarch, Boesman, P. & Kirwan, G.M. (2016). Illustrated Checklist of discovered by Dahl (1899) on 17 January, was situated the Birds of the World, Volume 2: Passerines. Lynx Edicions, in a vertical fork ~5 m above the ground. The outer layer Barcelona, Spain, & BirdLife International, Cambridge, UK. 58 Australian Field Ornithology V. Marcuk & D. de Boer

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