Start Year: First cohort
Host University: University of Liverpool
Department: Institute of Integrative Biology
Supervisors: David Atkinson, Liverpool
Skills and relevant qualifications:
ACCE PhD Research topic
Background: Recognition systems are ubiquitous in nature and play a critical role in interactions at every level of biological organization. In social species, the ability to discriminate among conspecifics determines the adaptive nature of decisions. Long-tailed tits Aegithalos caudatus discriminate kin from non-kin in two contexts: (1) helping decisions in their kin-selected cooperative breeding system; and (2) pairing decisions for inbreeding avoidance. Adults recognize kin using calls that are learned during early development (Sharp et al. 2005 Nature 434: 1127-1130). Objectives: (i) To record calls of birds of known relatedness to determine how vocal similarity varies with social and genetic kinship. (ii) To determine whether helping and pairing decisions are positive and negative functions, respectively, of call similarity. (iii) To model the fitness pay-offs from alternative helping and pairing decision rules, using inclusive fitness estimates measured in the field. Novelty: The ability to discriminate kin is extremely important in social organisms, yet the mechanisms involved are poorly known, especially among vertebrates. This will be the first study to investigate the similarity of recognition cues in the contexts of helping and mate choice and the fitness consequences of alternative discrimination rules. Our recent finding that long-tailed tits actively avoid inbreeding (Simeoni 2012, PhD thesis) creates the opportunity to study the role of recognition cue similarity in pairing decisions in the field. Moreover, current research includes estimation of inclusive fitness for a very large sample of birds, allowing parameterization of models of fitness pay-offs from alternative kin discrimination rules. Fit to ACCE: Evolutionary adaptation is subject to constraints imposed by mechanisms. Thus, an apparently maladaptive behaviour may result from decision rules that, on average, confer positive fitness benefits, but do not do so in all circumstances. Understanding these mechanistic constraints on adaptation is critical in the study of evolutionary processes and outcomes. The theoretical framework for studying recognition systems has been in place for over two decades, predicting that the strength of selection for effective mechanisms (and hence the error rate in decision-making) will depend on the relative fitness benefits of correct decisions and costs of incorrect decisions. However, the fundamental importance of constraints on effective kin recognition in determining individual fitness is often ignored, probably due to the paucity of good empirical examples. An understanding of such issues is particularly important in a changing environment where organisms are confronted by novel challenges for which their evolved mechanisms may be poorly suited. Fit to NERC: ‘Biodiversity’ is one of NERC’s seven science themes, recognising the importance of understanding the capacity of organisms to adapt to the challenges of a changing environment (see ACCE’s fourth focus). This capacity is a function of individuals’ responses to their biotic and abiotic environment. Our focus is on the behavioural decisions that individuals must make in all aspects of their lives, and the consequence of decision rules for individual fitness. But, the principles involved are general, and an understanding of the mechanistic basis for specific traits and their fitness consequences is essential in studying the effects of a changing environment on biodiversity. Access to fitness measures of alternative behavioural decisions in two contexts (mate choice and helping), with a known discriminatory mechanism, makes this project an excellent opportunity to contribute to this aspect of the NERC remit.