Identification of extremely high levels of mitochondrial DNA (mtDNA) sequence divergence within reptiles from North Africa is commonplace. This high divergence often compares with interspecific levels among widely accepted species, leading to the hypothesis of the occurrence of species complexes. Indeed, in many examples, data from nuclear markers support such taxonomic recognition. Such is the case of two recently recognized ocellated lizard species of the genus Timon, T. nevadensis, from Spain, and T. kurdistanicus, from the Middle East, which both showed notable genetic differentiation from their sister taxa. In North Africa, highly divergent mtDNA lineages of Timon tangitanus were previously identified but not corroborated with nuclear markers. Here we expand geographic sampling across the range of Timon tangitanus and complement mtDNA sequences with data from nuclear markers (MC1R and ACM4). We identify four divergent mtDNA lineages, at a level similar to some reptile species. However, the nuclear markers show limited differentiation and lack of lineage sorting. This and some other recent assessments within reptiles discourage the use of mtDNA data alone as a proxy for taxonomic units, demonstrating once more the need for integrative taxonomic approaches.

The diversity and the motor performance of birdsongs can both be sexually selected. In wood warblers, most species with high motor performance sing a greater proportion of trills, presumably to advertise performance, and thus have lower syllable diversity. We tested if this trade‐off between motor performance and syllable diversity extends to canaries, goldfinches and allies, a clade with much longer and more varied songs. We assembled a molecular phylogeny and inferred song motor performance based on the speed of frequency modulation either in trills or in within‐song intervals. The two metrics of performance were positively, but only mildly, related across species. While performance evaluated in intervals had high phylogenetic signal, performance evaluated in trills changed independently of phylogeny and was constrained by body size. Species in densely vegetated habitats sang fewer trills, but did not differ in motor performance. Contrary to wood warblers, song motor performance did not predict the proportion of trilled syllables nor within‐song syllable diversity, perhaps because large differences in the song duration of canaries, goldfinches and allies prevent trills from severely compromising syllable diversity. Opposed results in wood warblers and in these finches indicate the existence of clade‐specific trade‐offs in the evolution of birdsong.