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| Hylophilus moxensis van Els, Montenegro-Avila, Avalos, T. Wijpkema & J.T. Wijpkema, 2026 |
ABSTRACT
We assess the relationships of an undescribed taxon of Hylophilus (Aves, Passeriformes, Vireonidae) greenlet to the group containing Rufous-crowned Hylophilus poicilotis Temminck, 1822 and Grey-eyed Greenlet H. amaurocephalus Nordmann, 1835, two morphologically very similar species with a turbulent taxonomic past, using a mitochondrial (NADH2) and three nuclear genes (MUSK, ACO1, SPIN1). We recovered the two named species as sister taxa, having diverged ca. 3.5 mya, and both are distinct at each locus and with the combined multilocus dataset, confirming their previous recognition as species. By comparison, we found the isolated population from Beni, Bolivia, is sister to the branch containing both H. poicilotis and H. amaurocephalus. The Beni population is diagnostically distinct from similar H. amaurocephalus by the lack of black streaks or brown patch on the auriculars, and from H. poicilotis by the lack of black patch on the auriculars. Based on this combination of phylogenetic and morphological evidence, we describe this population of greenlet as a species separate from the other two. We compare vocalizations in the three species: the species from Beni has calls with harmonics as in female calls of H. amaurocephalus, but appears to have a distinct song with V-shaped notes. The newly-described Hylophilus is a resident endemic to marshland scrub in the semi-open landscape of the seasonally inundated savannas of Beni in central Bolivia, separated geographically by about 2000 km from its sister species.
KEYWORDS: Beni savannas, Llanos de Moxos, avifauna, Hylophilus, greenlet, phylogenetics.
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| Beni Greenlet Hylophilus moxensis sp. nov. in habitat near San Ramón, Beni, Bolivia, 10 January 2024 (Tini Wijpkema). Notice the pale brownish grey auriculars, combined with dark lores, dark base of commissure, rufous on the entire crown and frons, and dark irides. |
Hylophilus moxensis sp. nov.
P. van Els, M. Montenegro-Avila, N.A. Avalos, T. Wijpkema & J.T. Wijpkema. 2026. A New Species of Greenlet from Bolivia in the Hylophilus poicilotis/amaurocephalus group (Vireonidae). Avian Systematics. 3; 17-37. (1 January 2026)