A Nest of Orange-Throated Tanager Wetmorethraupis Sterrhopteron

Cotinga 36 Short Communications in the region is highly fragmented, not yet relocated the nest itself and the forest surrounding the and did not observe any activity nest was c.10 ha. therein. However, they observed While observing three adult- no adults carrying food or nest plumaged Wetmorethraupis material. As the terrain is very moving through the canopy of steep, the group was only detected the forest fragment from a dirt >300 m from the nest on several road, we noted that they were occasions (moving to or from the repeatedly visiting a particular nest). Therefore, based on the ease site within a palm tree and further with which this species is detected observations using binoculars and by its loud vocalisations, we telescope revealed that at least two consider that most of the periods birds were constructing a nest. of absence were spent in forest The nest was c.10 m above fragments other than that of the the steeply sloping ground, nest, and that the adults may have in the uppermost fronds of a moved 1 km or more during these walking palm Socratea exhorrhiza forays. Based on the extensive A nest of Orange-throated (identified as probably this experience of HFG with other Tanager Wetmorethraupis species by A. Henderson, New (albeit not closely related) species sterrhopteron York Botanical Garden, pers. with similar nesting and foraging comm.). Although we were unable habits to Wetmorethraupis Since its discovery7 in 1963, to examine it closely, on this or (i.e., Aphelocoma, Cyanocorax, Orange-throated Tanager subsequent visits, it appeared to Cyanolyca (Corvidae), Sericossypha Wetmorethraupis sterrhopteron be an open-cup nest, supported (Thraupidae), we believe that stands as one of the most from below by the woody rachis incubation was underway on distinctive and striking new bird of a palm frond, with little or no 16–19 February. On the morning species to be described in the past material interwoven with the of 20 February HFG located the half-century. This spectacular long-bladed leaflets on either side. nest during a period of adult tanager is restricted to humid The nest was c.1.5 m from the base absence. For fear of disrupting foothill forests in south-east of the frond and 3 m from its tip. their behaviour, he observed the Ecuador and northern Peru8,11. At least externally, it appeared to adults for four hours (08h00– Despite being found in disturbed be constructed primarily of twigs 12h00) from a vantage point that as well as intact habitats, its and other dead plant material. permitted approaches to the nest limited range has led BirdLife Some twigs bore mosses and to be observed, but precluded International1 to consider it lichens, but moss was apparently viewing the nest itself. During Vulnerable. As little has been not an important component of this period the group visited the published on its behaviour or the nest’s external architecture. nest area three times, and at least ecology, and the species’ breeding The nest was c.20–30 cm in three birds approached the nest. biology is completely unknown, we external diameter and overhung HFG did not observe food-carrying provide brief observations made by an adjacent frond shading by adults, but visits to the nest at a nest in extreme south-east and concealing it from above. were brief (1–3 minutes). While Ecuador. Adults made multiple trips to the the possibility exists that the DSW, MH, JM & Xavier Muñoz nest once every c.3–4 minutes birds were switching places with, discovered the nest on the morning over a 30-minute period on 30 or provisioning, an incubating of 30 January 2012 by a dirt January. Once, a bird sang while adult, their behaviour strongly road east of the río Nangaritza carrying either grass or a piece suggests that they were feeding and c.6 km south of the village of of palm frond to the nest. When young. Food items may have Orquídeas, prov. Zamora, Ecuador, HFG examined the presumably been too small to detect or were at an approximate elevation of completed nest on a subsequent perhaps regurgitated. On 21 1,000 m. The nest was located visit, he could detect no such February HFG videotaped the nest in disturbed tropical broadleaf material from below, suggesting at 06h00–13h00. The recording forest, and we observed active that grass-like materials may form revealed that the nest was not logging nearby. Canopy height was the nest lining. visited during this period, but c.15–20 m with just a few larger HFG & R. A. Gelis visited the adults were detected in the vicinity trees, i.e., Ocotea sp. (Lauraceae), locality on 16 February–9 March, twice (by their vocalisations). Ficus sp. (Moraceae) emerging and spent 4–6 hours each day in Until 28 February tanagers above younger trees including the nest’s vicinity. During the first were detected just four times in many second-growth colonisers four days, they detected tanagers the forest around the nest. It is such as Inga (Mimosaceae) and only periodically, with the entire probable that the nest was empty Cecropia spp. (Cecropiaceae). Most group of 4–5 adults moving noisily at this time, almost certainly due of the understorey vegetation in through the canopy around the to depredation given that <3 weeks the forest around the nest had nest. Unfortunately, they had had elapsed from construction been cleared. In general, habitat 115 Cotinga 36 Short Communications to feeding. It follows that, if our monotypic tanager of uncertain A. & Jonsson, R. (2007) interpretation of adult behaviour taxonomic affinities5. Both are Observations on the nesting is correct, the incubation period is large canopy dwellers, both travel and diet of the White-capped c.18–20 days. in (frequently) monospecific Tanager (Sericossypha On the morning of 22 February, flocks, and both vocalise loudly albocristata) in eastern at 09h15, HFG observed a large and frequently, and often move Ecuador. Orn. Neotrop. 18: flock of Russet-backed Oropendolas over long distances. Though the 139–142. Psarocolius angustifrons and only description of a Sericossypha 5. Hilty, S. L. (2011) Family Yellow-rumped Caciques Cacicus nest also lacks details4, its Thraupidae (tanagers). cela foraging in the canopy and architecture (bulky, loose-stick, In: del Hoyo, J., Elliott, subcanopy near the nest. Two open cup) and placement (atop a A. & Christie, D. A. (eds.) oropendolas visited the nest, but broad substrate) are apparently Handbook of the birds of the flew off after just 3–4 seconds similar to Wetmorethraupis. world, 16. Barcelona: Lynx with empty bills. Just as most Interestingly, the nests of Nemosia Edicions. of the flock had passed, five spp. tanagers9,14,15, the putative 6. Isler, M. L. & Isler, P. R. Wetmorethraupis arrived and relatives of Sericossypha5,12, are (1999) Tanagers. Second edn. vocalised loudly from nearby markedly dissimilar to those of London, UK: Christopher perches. None of the tanagers Orange-throated and White-capped Helm. approached the nest or otherwise Tanagers. As both latter species 7. Lowery, G. H. & O’Neill, J. acted aggressively towards the are infrequently included in P. (1964) A new genus and icterids, but all five continued phylogenetic analyses, their true species of tanager from Peru. to vocalise as they left with the affinities are unclear2,12. It remains Auk 81: 125–131. rapidly moving flock. It is possible to be seen if they are more closely 8. Marín A., M., Carrión B., J. that this same flock of icterids, related than currently believed, or M. & Sibley, F. C. (1992) which frequented the area during if the similarities above represent New distributional records our visits, was responsible for convergent evolution. for Ecuadorian birds. Orn. depredating the tanagers’ nest. Neotrop. 3: 27–34. HFG made final observations at Acknowledgements 9. Renaudier, A., Ingels, J. & the nest on 7 March. At 07h45 he We thank Xavier Muñoz and Hilty, S. L. (2008) Nesting heard vocalisations in the vicinity. Neblina Forest tours for taking and general behaviour of On his arrival he observed four the first three authors to this area. Hooded Tanager Nemosia birds, one of them 15 m from the HFG thanks Rudy A. Gelis for help pileata in French Guiana and nest with a 10–15 cm twig in in the field and Matt Kaplan, John Surinam. Cotinga 30: 54–56. its bill. However, all four moved V. Moore and Field Guides Inc. 10. Robbins, M. B. & Glenn, G. quickly from view through the for supporting his field work and S. (1988). First description forest canopy, still vocalising, until the staff of Yankuam Lodge for of the nest and eggs of they were no longer detectable their hospitality in the Nangaritza the Moss-backed Tanager when >150 m from the nest. It is Valley. (Buthraupis [Bangsia] probable the adults were removing edwardsi). Condor 90: material from the old nest in References 947–948. preparing to re-nest at a new site. 11. Schulenberg, T. S., Stotz, D. 1. BirdLife International Our observations strongly F., Lane, D. F., O’Neill, J. (2013) Species factsheet: suggest that Wetmorethraupis is a P. & Parker, T. A. (2007) Orange-throated Tanager cooperative breeder, a trait shared Birds of Peru. Princeton, NJ: Wetmorethraupis with numerous other genera of Princeton University Press. sterrhopteron. www.birdlife. Thraupidae5. Molecular data 12. Sedano, R. E. & Burns, org. (accessed 23 September indicate that Wetmorethraupis K. J. (2010) Are the 2013). is closely related to Bangsia12 for northern Andes a species 2. Burns, K. J. (1997) Molecular which all described nests have pump for Neotropical systematics of tanagers been mossy domes constructed in birds? Phylogenetics and (Thraupinae): evolution and epiphyte clumps or supported by biogeography of a clade of biogeography of a diverse small branches3,6,10,13.

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