Animal behaviour

I am an evolutionary biologist with a strong interest in animal behaviour. The main model system for my research is the fowl (red junglefowl and domestic fowl), but I also use other systems, such as insect models (Drosophila melanogaster, Callosobruchus maculatus).

My research questions fall within the following areas:

Why do animals have personalities?

Sexual selection and sexual conflict

Kin recognition and genetic incompatibility

The use of the fowl as a model species more generally
 

Why do animals have personalities? Despite the potential benefit offered by full plasticity in behavioural responses, we commonly find that behavioural responses are consistent within individuals over time and context. This consistent variation in behaviour among individuals is called personality. I am interested in the description and characterisation of behaviours along personality gradients, but even more interesting are the ultimate questions surrounding the evolution of personality, such as why individuals have personality, and the consequences it has. Thus, my research seeks to provide answers relating to the evolutionary origin, development and maintenance of variation in personality.

The fowl is a great model for research on animal personality for various reasons, for example, we know a lot about their behaviours, life-history and physiology, they are easily habituation to humans enabling observations and handling, and that their genome is sequenced. I primarily use the fowl as the model for my research on animal personality, but also use the seed beetle (Callosobruchus maculatus).

Collaborations
Mito-nuclear variation and animal personality in Callosobruchus maculatus: Göran Arnqvist
Domestication and personality: Per Jensen, Dom Wright
Animal personality, differential sperm allocation and mating success in the fowl: Tom Pizzari
Animal personality and social dominance in the fowl: Anna Favati Carlsson, Tommy Radesäter, Olof Leimar
 

Sexual selection and sexual conflict –what predicts the outcome of a copulation? In polyandrous species mechanisms that affect the outcome of a copulation can act both before and after insemination, including competition over access to partners, partner choice, sperm competition and cryptic female choice. Studies on sexual selection may become even more complicated and fascinating when the reproductive goal of the sexes diverge, creating the potential for sexual conflict over the control of copulation and fertilisation. As a result, sex-specific and counteracting responses may take place.

The fowl is particularly well-suited for studies of sexual selection because they are promiscuous and females store sperm in thousands of sperm storage organs for around 2 weeks creating intense sperm competition and the potential for cryptic female choice. And both sexes respond to this in sophisticated ways; males allocate sperm strategically dependent on a range of cues (for example, their own status, the number of males they face competition from, female quality) and females by biasing their sperm use (for example by ejecting ejaculates from non-preferred males). How males allocate sperm strategically and females bias sperm use is however still unclear to us.

I also use of the fruit fly, Drosophila melanogaster, which is another great model for research on sexual selection and sexual conflict, the later due to male seminal fluid proteins that make mating costly to the female.

Collaborations
Sexual selection and sexual conflict in the fowl: Tom Pizzari, Rebecca Dean
Sexual conflict in Drosophila: Urban Friberg, Alexei Maklakov, Simone Immler

Kin recognition and genetic incompatibility. Inbreeding, when closely related individuals breed, may impose costs to individuals due to the increased risk of expressing deleterious recessive alleles in the offspring. As a cue for genetic relatedness or independently of it, fertilisation may also be influenced by MHC (Major Histocompatibility complex) similarity between partners. Particularly the sex investing most in the offspring (typically females) should consider this, which may create sex-specific responses to inbreeding and MHC similarity between partners. I am interested in how individuals are able to recognise kin and genetic dissimilarity, and how this affects mate choice, sperm competition and cryptic female choice.

Collaborations
Responses to risk of inbreeding in Drosophila:
Stuart Wigby, Cedric Tan, Tom Pizzari
MHC, inbreeding and cryptic female choice in the fowl: Tom Pizzari, David Richardson

The use of the fowl as a model species more generally. Beyond the research areas mentioned above, I believe that the red junglefowl and domestic fowl are exceptional models for a range of questions where an experimental approach is beneficial. For instance, I am involved in research using fowl to investigate olfaction in birds, as a model for bird vision, and as a predator to help improve our understanding of predator-prey interactions with concerns to the evolution of eyespots and aposematism.

Collaborations
Avian olfaction: Josefina Zidar
Bird vision: Anders Ödeen
Eyespot evolution: Martin Olsson, Christer Wiklund, Sven Jakobsson
Evolution of aposematism: Birgitta Tullberg. 

Free-ranging fowl at Tovetorp Zoological research station (Stockholm University).