Postgraduate Profiles

Callum Donohue

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Thesis: Understanding the effect of context of escape responses in fiddler crabs

My research aims to better understand the neural mechanisms that underlie predator evasion and decision making in animals. To do this, I use fiddler crabs as a model system to help develop our understanding of contextual influences on escape behaviour.

Recently, the application of a robotic test platform (RoboCrab), has raised a number of issues that concern the integration of escape behaviours into the larger behavioural repertoire of crabs. This includes the interactions between escape behaviour and navigation, as well as the influence of other environmental contexts on escape decisions. Consequently, I will explore the exact predator stimulus parameters that elicit escape responses in the laboratory in combination with how fiddler crabs update predator information during their run to the safety of the burrow. In addition, I will test how this may interact with the referencing systems used by the crabs to accurately navigate their way home.

We are also becoming progressively more aware that context has a powerful influence on animal behaviour and therefore making it difficult to interpret laboratory results in a natural context. As such, I will target the contextual information that is responsible for the observed differences between laboratory and field studies. In order to improve our ability to interpolate between laboratory and field studies, I will use a two pronged approach. Firstly, develop modifications to commonly used laboratory techniques, to incorporate a burrow, allowing me to measure how the presence or absence of a refuge affects anti-predator decisions. Secondly, develop a device capable of taking electrophysiological recordings from a crab in the field. The successful application of this device will allow us to record directly from neurons in an evolutionary relevant environment and compare this to the neural responses measured in the laboratory.

Why my research is important

Once completed, these aims will help us understand the neural mechanisms that guide behaviour and decision making in an example of a small central place forager. The findings from this work will also inform the design of autonomous robots for which decision making is a key challenge. My research will allow more feasible correlations between laboratory results and field conditions and by extension, help to truly understand how ecologically relevant information is being processed by the visual-nervous system.


An accelerometer attached to the carapace of a fiddler crab (Uca pavo) to better understand the day - to - day beahviour of the species

Jun 2017

Jun 2020