9/10 Overall, our research underscores the need to incorporate hybridization and its contribution to evolutionary resilience in future conservation plans for endangered taxa.

(Photo by Víctor París)

8/10 Through forward simulations we show that the protection of hybrid colonies will safeguard the genetic diversity of the Balearic shearwater under potential bottlenecks in the long run. Nevertheless, mitigating bycatch-linked mortality should still be the nº1 conservation priority.

7/10 We observe a lack of differences in genetic diversity and genetic load among shearwater populations, which we attribute to the pervasiveness of gene flow between them. Hybridization has prevented #inbreeding in the collapsing populations of Balearic shearwaters.

6/10 Hybridization has enabled the exchange of adaptive haplotypes between shearwater taxa in regions that host candidate genes underlying differences in migratory strategies. This process might enhance the adaptive potential of shearwaters in the face of climate change.

5/10 We show that Balearic-Yelkouan introgression permeates throughout both species’ ranges. Nevertheless, it is most prominent in the islands where the ranges of both species meet: Menorca and Cabrera.

4/10 We uncover a complex demographic history shaped by periods of isolation during glacial maxima and widespread hybridization during interglacial periods. The latter explains the near lack of differentiation between these 2 shearwater taxa at the genomic level!

3/10 Five years ago we set out to explore the role of hybridization between the Critically Endangered Balearic shearwater and the Yelkouan shearwater using whole-genome resequencing data. After years of intense work, we’re glad to share our results in this thread!