LARGE SCRUBWREN Sericornis nouhuysi

Commonȱ alongȱ withȱ Buff-facedȱ Scrubwrenȱ S. perspicillatus at high elevations, singing its characteristicȱgerygone-likeȱsong.ȱCollectedȱbyȱGilliardȱandȱbyȱPratt,ȱandȱdescribedȱbyȱPrattȱ (1982) as an endemic subspecies. The taxonomic relationship between S. nouhuysi and its low-elevation sibling Tropical Scrubwren S. beccarii has been much debated because of the confusing geographic variation in plumage of S. beccarii (Diamond 1969, 1985, Beehler & Prattȱ 2016).ȱ However,ȱ theirȱ ecologicalȱ relationshipȱ isȱ simpleȱ andȱ clear:ȱ theyȱ segregateȱ byȱ elevation at c. 1,400 m wherever they co-exist (e.g., Kumawa, Foja, north slopes of western Newȱ Guinea’sȱ Centralȱ Range).ȱ Eachȱ speciesȱ isȱ confinedȱ toȱ approximatelyȱ thatȱ sameȱ elevational range in the absence of the other (e.g., S. beccarii in the North Coastal Range and Wandammen, S. nouhuysi in Huon and the northern watershed of the eastern Central Range). The Adelbert population of S. nouhuysi fitsȱthisȱpattern:ȱitȱisȱconfinedȱtoȱelevationsȱ above 1,535 m despite the absence of S. beccarii, which reaches its eastern distributional limit in the northern watershed of the North Coastal Range 160 km west of the Adelberts.