Dr Lena Grinsted
I study the evolution of group living. I am interested in understanding how animals have evolved to reap the benefits of living, feeding, and breeding in groups while minimising the inevitable costs of competing with group members for limited resources. I primarily use group living spiders as my model organisms, although I also work with social insects such as ants and wasps.
Group living is only found in a small number of spider species. Some spider species are cooperative breeders, comparable to social groups of lions or primates. Other spider species are colonial meaning that they live in groups but maintain solitary territories within the group. Spider groups can be formed by hundreds or thousands of individuals, and are mainly found in tropical and subtropical parts of the world. Within these magnificent groups, spiders show some fascinating behaviours such as hunting together, sharing food, building their silken nest together, and helping to protect and feed each other’s young.
Spiders are fantastic to work with. They are always charismatic, they offer large sample sizes, and spider colonies are easy to capture, transport and manipulate. Spiders can further be kept solitarily or in groups to estimate costs and benefits of group living.
Examples of research directions:
Cooperative breeding and helping behaviour
Many social animals cooperate in brood care, helping to feed and protect other group members’ young. I am interested in identifying adaptations to cooperative breeding.
For example, I investigated maternal effects in several social and non-social spider species by collecting, counting and measuring the size of eggs within egg sacs. I found that social spiders laid fewer, larger eggs than their non-social counterparts (doi: 10.1111/evo.12411). This suggests that social species have adapted to group living by investing in quality over quantity of young due to competition for limited resources within groups, and due to the benefits of shared maternal care such as better growth and survival of young.
In a different project I investigated how paper wasps in Spain chose their social partners. I found that helpers’ social decisions may be influenced by a biological market where the supply and demand for helping behaviour determines how much help they are willing to provide (doi: 10.1038/ncomms13750; doi: 10.1098/rspb.2017.0904).
Adoption of foreign offspring
Mothers typically care for others’ young in two different cases: In social, cooperatively breeding societies or in cases where mothers are being manipulated by brood parasites to care for parasitic young. Brood adoption is exceedingly rare outside of these types of systems. Hence, it was highly intriguing when I discovered brood adoption within mixed-species Chikunia spider colonies on Bali, Indonesia. Here, I found two sister-species living together in colonies (doi: 10.1007/s00114-012-0983-4). One of the two species was new to science and I recently described and named it (doi: 10.1093/zoolinnean/zly083). I am interested in several questions within this system relating to the interactions between the two species; whether females adopt offspring both within and between species; and how groups form.
Many animals forage in groups. Group foraging can be more or less cooperative, ranging from foraging flocks of birds wherein individuals show little direct interaction, to highly cooperative group hunting as seen in lions. I revisit and extend upon classic foraging theories such as risk-sensitive foraging theory and the central limit theorem (doi: 10.1111/evo.13826) and the hypothesis that group hunting allows for the capture of larger prey (doi: 10.1007/s00427-019-00640-w). In both examples I have provided new theoretical frameworks, supported by data on spider foraging, to better understand the selection pressures shaping group foraging in a range of group living organisms.
- Sara Goodacre and Ella Deutsch, University of Nottingham, UK
- Angelika Stollewerk and Magdalena Ines Schacht, Queen Mary University of London, UK
- Yael Lubin, Ben-Gurion University of the Negev, Israel
- Manuel Jimenez Tenorio, Cadiz University, Spain
- Trine Bilde and Virginia Settepani, Aarhus University, Denmark
- Anom Bowolaksono, University of Indonesia, Indonesia
- Ni Luh Watiniasih, Udayana University, Indonesia
- Senior Lecturer in Zoology, School of Biological Sciences, University of Portsmouth, UK, 2020-present
- Leverhulme Early Career Research Fellow, School of Biological Sciences, Royal Holloway University of London, UK, 2017-2020
- Postdoctoral Research Fellow, School of Life Sciences, University of Sussex, UK, 2013-2016
- PhD in Evolutionary Biology, Department of Bioscience, Aarhus University, Denmark, 2010-2013
- MSc in Biology, Centre for Social Evolution, University of Copenhagen, Denmark, 2006-2009
- BSc in Biology, University of Copenhagen, Denmark, 2003-2006*
- *Included a study abroad for my BSc thesis at the School of Biological, Earth and Environmental Sciences, University of New South Wales, Australia, 2006