I work on a variety of theoretical biological problems ranging from the effects of human disturbance on natural systems to studying how population level behavioural traits have evolved, often with a focus on marine mammals, and using a wide variety of mathematical techniques. Most of my work focuses on two areas:
1) The effects of disturbance on natural communities or populations
My work in this area has focused on a variety of scales, ranging from whole ecosystems such as rain forests to individual animals. The focus has been on developing theory that allows us to understand and predict the consequences of altered disturbance patterns. These predictions range from measures that can be used to assess the impact of disturbance on a single individual to assessments of the effects of disturbance on ecosystem level species-richness.
2) The impact of social behaviour on evolutionary and ecological traits within a population
Social behaviour can have a dramatic impact on the pressures experienced by individuals or populations, at both ecological and evolutionary time scales. One aspect of this impact is the evolution of social interactions that come with an evolutionary cost for the social individual, which may be offset by inclusive fitness benefits, where assisting related individuals can boost the proportion of your genes passed on to the next generation. I am currently working on the evolution of menopause, where the direct fitness of an individual is lowered by ceasing to reproduce long before the end of life. We are examining what the potential inclusive fitness benefits of this reproductive cessation are in killer whales, one of only 3 mammal species who exhibit a long post-reproductive lifespan.
Publications
7) Postreproductive lifespans are rare in mammals
S Ellis, DW Franks, S Nattrass, MA Cant, DL Bradley, D Giles, KC Balcomb, DP Croft
Ecology and evolution 8 (5), 2482-2494
6) Mortality risk and social network position in resident killer whales: sex differences and the importance of resource abundance
S Ellis, DW Franks, S Nattrass, MA Cant, MN Weiss, D Giles, KC Balcomb, DP Croft
Proc. R. Soc. B 284 (1865), 20171313 (link)
5) Reproductive conflict and the evolution of menopause in killer whales
DP Croft, RA Johnstone, S Ellis, S Nattrass, DW Franks, LJN Brent, S Mazzi, KC Balcomb, JKB Ford, MA Cant
Current Biology 27 (2), 298-304 (link)
4) Using resilience to predict the effects of disturbance. (2016)
S Nattrass, D Lusseau
Scientific Reports 6, 25539 (PDF)
3) The significance of post-reproductive lifespans in killer whales: Reply to Robeck et al. (2016)
Franks DW, Nattrass S, Brent LJN, Whitehead H, Foote AD, Mazzi S, Ford JKB, Balcomb KC, Cant MA, Croft DP
Journal of Mammalogy. (published online March 2016)
2) Quantifying the Likelihood of Co-existence for Communities with Asymmetric Competition (2012)
S Nattrass, S Baigent, DJ Murrell
Bulletin of mathematical biology 74 (10), 2315-2338 (PDF)
1) A study of the dynamics behind methane emissions from northern wetlands (2010)
S Nattrass
Bioscience Horizons 3 (1), 57-65 (PDF)