Mitochondrial phylogeography of the Eurasian Reed Warbler Acrocephalus scirpaceus and the first genetic record of A. s. fuscus in Central Europe

Abstract

The phylogeography and evolutionary history of the long‐distance migratory Eurasian Reed Warbler Acrocephalus scirpaceus were analysed using sequence data from the mitochondrial DNA COI gene of 405 individuals and cyt b sequences from a subset of those individuals from 20 breeding, migrating and wintering populations over its wide geographical range. Median‐joining network and Bayesian phylogenetic analyses recovered three lineages corresponding to three subspecies of A. scirpaceus that started to diverge approximately 480 000 years ago: one spanning Asia (Acrocephalus scirpaceus fuscus), one encompassing Europe and Northern Africa (Acrocephalus scirpaceus scirpaceus) and a third that included Eastern Africa and Southwestern Asia (Acrocephalus scirpaceus avicenniae). Phylogenetic analyses suggest that the third clade is basal and diverged from its sister species, the African Reed Warbler Acrocephalus baeticatus, around 700 000 years ago. This earliest subspecies (avicenniae) may have survived the Last Glacial Maximum in one of the African refugia, probably the low forest refugium of the Ethiopian Highlands. Sequences of 348 samples from Germany, which were captured for ringing, showed that one bird was genetically assigned to the subspecies fuscus, the first genetic evidence of this Asian subspecies in Central Europe. According to our DNA sequences, 6.8% of Eurasian Reed Warblers were misidentified at the species level, Marsh Warbler Acrocephalus palustris accounting for most of these misidentified specimens. At the subspecies level, of 22 fuscus identified by genetic analyses, only six had been correctly named by the ringers.

Does fragmentation of wetlands affect gene flow in sympatric Acrocephalus warblers with different migration strategies?

“…Both species showed signs of postglacial expansions, consistently with the findings of other studies of European wetland passerines (Hansson et al , Neto et al , Arbabi et al ). Haplotype diversity was higher for reed warblers, possibly because of a more important contribution of dispersal from different populations, past admixture of differentiated lineages and the higher population size (Fig.…”

“…The haplotype and nucleotide diversities we obtained were higher (n = 50; h = 0.745; π = 0.006) than estimated for Germany (n = 347; h = 0.544; π = 0.002) or for subspecies scirpaceus (n = 380; h = 0.558; π = 0.002) in Arbabi et al (). The higher genetic diversity could be linked to an older population, i.e.…”

“…) is compatible with a postglacial expansion from a refugium area, as the climate became warmer, causing the expansion of the suitable habitat also for many other species (Murray Gates , Wright et al , Hewitt , Dubey et al ). Arbabi et al () identified three mitochondrial lineages corresponding to three subspecies ( scirpaceus, fuscus and avicenniae ) of reed warblers and suggested these had remained isolated in three different glacial refugia during the Middle Pleistocene glaciations. Procházka et al () suggested that it is possible that the Iberian Peninsula was one of the refugium areas for reed warblers, as has been documented for many other species (Hewitt ).…”

“…Proch á zka et al (2011) suggested that it is possible that the Iberian Peninsula was one of the refugium areas for reed warblers, as has been documented for many other species (Hewitt 2004). Evidence of past population growth in reed warblers was detected also by Arbabi et al (2014), but their samples were mainly from Germany.…”

Equipped to cope with climate change: traits associated with range filling across European taxa

“…range filling) will inform whether that species is likely to colonise the newly suitable habitat (Svenning and Skov 2004, Dullinger et al 2012, Estrada et al 2015. This is particularly true for Europe, where species ranges are thought to be strongly shaped by the ability to expand from glacial refugia (Hewitt 1999, Arbabi et al 2014, which is known to relate to some species traits (Svenning and Skov 2004, Dullinger et al 2012, Estrada et al 2015.…”