The evolution of north‐east Atlantic gadfly petrels using statistical phylogeography

Abstract

Macaronesia (north-east Atlantic archipelagos) has been host to complex patterns of colonization and differentiation in many groups of organisms including seabirds such as gadfly petrels (genus Pterodroma). Considering the subspecies of widely distributed soft-plumaged petrel for many years, the taxonomic status of the three gadfly petrel taxa breeding in Macaronesia is not yet settled, some authors advocating the presence of three, two or one species. These birds have already been the subject of genetic studies with only one mtDNA gene and relatively modest sample sizes. In this study, using a total of five genes (two mitochondrial genes and three nuclear introns), we investigated the population and phylogeographical histories of petrel populations breeding on Madeira and Cape Verde archipelagos. Despite confirming complete lineage sorting with mtDNA, analyses with nucDNA failed to reveal any population structuring and Isolation with Migration analysis revealed the absence of gene flow during the differentiation process of these populations. It appears that the three populations diverged in the late Pleistocene in the last 150 000 years, that is 10 times more recently than previous estimates based solely on one mtDNA gene. Finally, our results suggest that the Madeira petrel population is ancestral rather than that from Cape Verde. This study strongly advocates the use of nuclear loci in addition to mtDNA in demographical and phylogeographical history studies.

Population size, breeding biology and on-land threats of Cape Verde petrel (Pterodroma feae) in Fogo Island, Cape Verde

“…During most of this period, Desertas and Zino’s petrels are wintering and therefore they have little chance to interbreed with those from Cape Verde. This asynchrony in the breeding phenology can contribute to speciation in another Procellariiform species [37] and thus supports a currently independent evolution of the three lineages [6]. …”

“…Cape Verde and Desertas petrels have recently been split from the ancestral Zino's petrel ( Pterodroma madeira; [5,6]) breeding in Madeira Island. A further split between Cape Verde petrel, endemic from Cape Verde, and the Desertas petrels ( Pterodroma deserta) , breeding in Desertas Is.…”

“…For example, biometric differences between Cape Verde and Desertas petrel are unclear [7], have not been formally tested and may be obscured by sexual size dimorphism, since no study reported biometric measures of males and females separately. Nevertheless, a growing number of differences, based on bioacoustics [8], molecular genetics [6,9] and spatial ecology [10], support Cape Verde petrel should be considered a different species from its sister taxa. Unfortunately, unlike the Desertas petrel, which has been intensively studied and managed over the last 30 years [11,12], no specific studies and conservation measures have been undertaken on Cape Verde petrels so far.…”

Late Holocene range collapse in a former British seabird species

“…Our estimates for the dates of the most recent common ancestors for other clades within the north‐east Atlantic Pterodroma radiation are given in Table ; these estimates are consistently older than those of Gangloff et al . (), owing to the different methodologies employed between our study and theirs.…”

“…2.5 million years ago, whereas Gangloff et al . () used two mitochondrial genes and three nuclear introns to estimate much more recent divergences of c . 153,000 years ago (95% highest posterior density, HPD: 47,000–359,000) for P .…”