Leach’s storm petrel

Behavioural ecology of albatrosses, petrels and shearwaters

23 February 2018

Dr Simon Sin’s research on behavioural genomics explain bird size and mate choice.

Dr Simon Yung Wa Sin (Croucher Scholarship 2008) is a postdoctoral fellow at the Department of Organismic and Evolutionary Biology at Harvard University, USA. Sin’s research aim is to understand how genetics affect phenotypic traits and behaviours. This span the fields of molecular ecology, evolutionary biology and behavioural genomics.

Albatrosses, petrels and shearwaters: the birds that make up the order Procellariiformes, including some of the most endangered species of bird on the planet. Sin is currently conducting research on behavioural genomics of the Leach’s storm petrel, specifically, on evolutionary genomics of mate choice, speciation, introgression and genotype-phenotype association.

Leach’s storm petrel, like many other species, face the danger of extinction posed by rising sea levels. This species nests on islands now prone to flooding, which can wipe out entire populations if flooding takes place during the incubation and preflight chick period. One solution to this problem is to relocate seabird colonies onto islands where there is a reduced risk of flooding. Sin’s research into genetic diversity within seabird species has potential implications in deciding which seabirds are translocated, in order to give these species the best chance of survival in a new environment.

An interesting outcome of Sin’s research has been his discovery that, while Leach’s storm petrels are well-known for being socially monogamous, infidelity is also prevalent within the species. Sin has used next-generation sequencing (NGS) technologies in order to develop genetic markers which allow him to explore a potential relationship between genetic diversity within an individual, and their morphological traits. It was found that there was indeed a relationship, with mothers who had lower heterozygosity producing chicks which were generally smaller in size.

This has been a concerning finding, as it indicates that reduced heterozygosity within an individual was depressing the size of offspring and therefore may adversely affect the individual’s fitness. This reduction of individual heterozygosity happens more often in inbred populations. It is important to consider heterozygosity in relation to conservation, as greater genetic diversity is key to the survival and fitness of a species. Sin’s research could provide useful information regarding which birds should be chosen for translocation, for example, choosing pairs of animals that are more compatible genetically, as well as pairs which have a higher chance of producing fit, healthy offspring and that therefore have a higher chance of survival. Individuals that can contribute to the genetic diversity of the recipient population could also be chosen.

Mate choice is another strand of Sin’s research. In particular, what causes an individual to choose one mate over another. Sin is exploring the impact of mate choice, and advantages that might come from successful mating, such as choosing a mate with compatible genes. For example, some seabirds have been found to make their choice of mate based on major histocompatibility complex (MHC) genes. MHC genes differ from individual to individual, and encode MHC molecules on the cell surface which detect foreign antigens for the immune system to fight against invading pathogens. Choosing a partner with different MHC genes increases the likelihood of offspring having more heterozygous MHC genes. It is possible that MHC genes are linked to the body odour of an animal, allowing them to make their choice based on this. Sin’s collaborative research into Leach’s storm petrel also found that males prefer female mates which are more heterozygous at genetic level.

Pairing mating choice with genetic compatibility for the best chances of mating occuring, and successfully (to produce healthy chicks with a strong chance of survival and genetic diversity), Sin hopes to contribute towards the ongoing conservation efforts for these birds. 

Dr Simon Yung Wa Sin is a postdoctoral fellow in the Department of Organismic & Evolutionary Biology at Harvard University. He obtained a BSc degree in Biology with first class honours at the Chinese University of Hong Kong (CUHK) in 2005, and an MPhil degree in Biology at CUHK in 2008. He was awarded a Croucher Scholarship and joined the Wildlife Conservation Research Unit in the Zoology Department at the University of Oxford, where he accomplished his DPhil study in 2013. His research currently focuses on the Leach’s storm petrel and other bird species at Harvard University.

To view Dr Sin’s Croucher profile, please click here.