PhD Studentship - Costly Signalling and Mate Search in wild Fiddler Crabs

Sexual selection is a potent evolutionary force, responsible for astonishing diversity in morphology and behaviour. To understand how such striking displays have evolved, we need to know (1) how individuals adjust their display behaviour depending on the social environment and their own physiological state; and (2) how individuals choose among potential mates whose displays change rapidly over time. This PhD project will tackle these questions using a combination of evolutionary modelling and cutting-edge behavioural experiments in a wild population of West African fiddler crabs (Afruca tangeri). The theoretical component will involve building models (using dynamic programming, or evolutionary computer simulations, or both) to predict adaptive strategies for courtship and mate search. The empirical component will involve field trips (May-July) to our study site in southern Portugal, where thousands of fiddler crabs can be studied at close quarters in their natural environment. In this species, male crabs develop an enlarged major claw (around 30% of their body weight) that they use in waving and drumming displays to attract females. We have recently developed techniques to measure the energetic costs of male courtship in real time using flow-through respirometry, and to simulate competition from rival males using biomimetic robots. We can also follow the detailed mate-search behaviour of female crabs using miniature Bluetooth devices and automated video tracking. Our supervisory team is an interdisciplinary collaboration across the DLTP partnership and will provide bespoke training in behavioural fieldwork (Darden—Exeter), ecophysiology and sensory ecology (How—Bristol), game theory and evolutionary simulations (Fawcett—Exeter), as well as more general skills including data analysis and scientific writing. There are many exciting directions the work could take and we are especially keen to hear from students who want to play an active role in designing the project. Further reading: Wilde et al. (2025) doi.org/10.1098/rspb.2025.1570 Hollon et al. (2023) doi.org/10.1007/s00265-023-03296-9 Funding For eligible students the studentship will cover home tuition fees plus an annual tax-free stipend.