Historical demography of the Balearic shearwater
Balearich shearwater PSMC’ analysis showed support for a steady growth in population size from an originally low population size followed by a sudden increase ~200 kya (Figure 1c). High population size did not last long and suffered a sudden decrease to nearly one tenth of the population coinciding with the end of the glacial period before the last interglacial period (119-128 kya) and a prolonged period of low sea level (Figure 1c). Hereafter, N eremained stable until ~10 kya ago, as more recent MSMC2 time segments are regarded as being unreliable (Schiffels & Wang, 2020).
Genome-wide heterozygosity in P. mauretanicus was 0.0024, which is within the range of genome-wide heterozygosities estimated for other Procellariiformes (ranging from 0.0014 in T. chlororhynchos to 0.0037 in P. urinatrix) (Figure 2a). Among Procellariiformes, small-bodied species tended to have higher mean heterozygosities but also higher variance than large-bodied species (Figure 2b).