Investigating trade-offs in Strength, Skill and Vigour in Pagurus Bernhardus

The ability to win contests is vital for securing the valuable resources individuals <br/>need for survival, or in some cases to secure mating opportunities. Therefore, <br/>fighting can have a strong influence over fitness, and much research has been <br/>carried out to identify and understand the traits influencing fighting ability, also <br/>known as resource holding potential (RHP). RHP has been found to be <br/>influenced by a wide range of factors including morphology, physiology, vigour <br/>and, more recently, skill. These factors are typically analysed in isolation from <br/>one another, so as to identify the individual impact of each trait. However, to <br/>gain a more comprehensive understanding of RHP we would benefit from <br/>identifying how these different traits potentially interact and trade-off with one <br/>another to determine overall RHP. Strength is relatively under-researched in the <br/>context of fighting, therefore we know very little about how it affects fighting <br/>behaviour or other RHP traits. Using the European hermit crab Pagurus <br/>bernhardus, we investigated the relationship between three RHP traits: <br/>strength, vigour and skill. We identified a potential trade-off between strength <br/>and skill, indicating that individuals might have to choose between different <br/>agonistic strategies. In contrast, vigour appears to be unrelated to strength, <br/>suggesting that the two factors are influenced by independent sets of traits. The <br/>near universal investment in vigorous fighting amongst the majority of<br/>individuals, while strength and skill appear to trade-off (perhaps in competition <br/>for limited energetic budget) implies that some RHP traits might be considered <br/>more important than others and thus receive greater investment. We may have <br/>also identified a potential measure of efficiency, that being gripping style, where <br/>some individuals appear to apply their strength in shorter bursts of force, which <br/>might better suit fighting which involves brief periods of agonistic behaviour, and <br/>prolonged rests. In conclusion, our results indicate that there are numerous <br/>complex links between different RHP traits which in some cases force trade offs. Therefore, we should make attempts to study fighting behaviour more <br/>holistically, if possible, rather than considering them each in isolation. <br/>

Author dc:creator

• Le Pla, Joshua

Contributors dc:contributor

• Mark Briffa, Sarah Lane

• Animal Behaviour

Language dc:language

eng

Repository record dc:identifier

https://pearl.plymouth.ac.uk/bms-theses/461

OAI identifier oai:identifier

oai:pearl.plymouth.ac.uk:bms-theses-1460