Evolutionary divergences in Luscinia svecica subspecies complex – new evidence supporting the uniqueness of the Iberian bluethroat breeding populations
P. 141-149The assessment of evolutionary divergences within subspecies complexes provide an effective
short-cut for estimating intraspecific genetic diversity, which is relevant for conservation
actions.We explore new evidence supplementing the existing knowledge about
the singularity of Iberian bluethroats within the Luscinia svecica subspecies mosaic.We
compared biometric traits of Iberian males (L. s. azuricollis) to the closest subspecies (L.
s. cyanecula, L. s. namnetum and L. s. magna) using general linear models and analysed
the correlations between biometric and genetic differentiation (based on nuclear microsatellites)
among the target subspecieswith aMantel test. Biometric differenceswere calculated
using 63 museum skins and 63 live specimens. Genetic distances were estimated
in a sample of 136 individuals. An additional characterisation of the plumage of Iberian
males was shaped from 22 live specimens. We highlight the distinctiveness of Iberian
birds within the subspecies mosaic since L. s. azuricollis had longer wings than L. s.
cyanecula and L. s. namnetum, but shorterwings than L. s. magna. Indeed, L. s. azuricollis
had longer tarsus and bill than L. s. namnetum, but shorter bill than L. s. magna. Biometric
divergence was not significantly associated with genetic distance. Iberian males showed
an all-blue plastron in 77% of specimens, a mostly non-marked black band and no white
band, which distinguished them from males of L. s. cyanecula and L. s. namnetum. We
conclude the importance of considering phenotypic and genotypic differences at subspecies
level, which is essential for designing realistic conservation strategies addressed to
preserve species genetic diversity patterns.
1. Introduction
The presence of endangered species is currently
one of the main principles for establishing priorities
of conservationS