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Innovations in nest design are thought to be one potential factor in the evolutionary success of passerine birds (order: Passeriformes), which colonized new ecological niches as they diversified in the Oligocene and Miocene. In particular, tyrant flycatchers and their allies (parvorder: Tyrannida) are an extremely diverse group of New World suboscine passerines occupying a wide range of habitats and exhibiting substantial extant variation in nest design. To explore the evolution of nest architecture in this clade, we first described nest traits across the Tyrannida phylogeny and estimated ancestral nest conditions. We then quantified macroevolutionary transition rates between nest types, examined a potential coevolutionary relationship between nest type and habitat, and used phylogenetic mixed models to determine possible ecological and environmental correlates of nest design. The Tyrannida ancestor probably built a cup nest in a closed habitat, and dome nests independently evolved at least 15 times within this group. Both cup- and dome-nesting species diversified into semi-open and open habitats, and we did not detect a coevolutionary relationship between nest type and habitat. Furthermore, nest type was not significantly correlated with several key ecological, life-history and environmental traits, suggesting that broad variation in Tyrannida nest architecture may not easily be explained by a single factor. This article is part of the theme issue ‘The evolutionary ecology of nests: a cross-taxon approach’.

The diverse Old World avian family Ploceidae (weaverbirds) presently comprises 117 species in 17 genera. Despite being a well-known bird group, the family has received incomplete attention in terms of molecular systematics; systematists have often focused on subclades, with the most extensive study to date covering <66% of recognized species. As a consequence, weaverbird taxonomy remains outdated, and phylogenetic relationships, particularly of the African Malimbus (previously Ploceus and Malimbus) clade, remains largely unresolved. Here, we sampled 109 weaver species (and numerous nominal subspecies), including 99 of the 103 recognized “typical weaverbird” taxa for an 8-gene dataset. Antique DNA techniques were used to extract DNA from study skins of 27 rare taxa not available in global tissue collections. The study included 32 species and 4 genera of ploceids previously unstudied phylogenetically. Our analyses supported monophyly of the family and identified 8 distinct clades. Our results conflict extensively with current taxonomy. We suggest that plumage traits and morphology exhibit high plasticity, such that phenotype does not always reflect phylogenetic relationships in weaverbirds. We recommend (1) uniting African-Ploceus, Malimbus, Anaplectes, and Notiospiza in Malimbus; (2) retaining the monotypic genus Pachyphantes; and (3) placing Brachycope with Euplectes. This study, the first near-species-level phylogeny for the family, lays a firm foundation for downstream studies of biogeography and character evolution.

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