Prey animals have evolved a wide variety of behaviours to combat the threat of
predation, many of which have received considerable empirical and theoretical
attention and are generally well understood in terms of their function and
mechanistic underpinning. However, one of the most commonly observed and
taxonomically widespread antipredator behaviours of all has, remarkably, received
almost no experimental investigation: so-called ‘protean’ behaviour. This is defined
as ‘behaviour that is sufficiently unpredictable to prevent a predator anticipating in
detail the future position or actions of its prey’. In this thesis, I have elucidated the
mechanisms that allow protean behaviour to be an effective anti-predatory
response. This was explored with two approaches. Firstly, through the novel and
extremely timely use of virtual reality to allow human ‘predators’ to attack and chase
virtual prey in three-dimensions from a first-person perspective, thereby bringing the
realism that has been missing from previous studies on predator-prey dynamics.
Secondly through the three-dimensional tracking of protean behaviour in a highly
tractable model species, the painted lady butterfly (Vanessa cardui). I explored this
phenomenon in multiple contexts. Firstly, I simulated individual protean prey and
explored the effects of unpredictability in their movement rules with respect to
targeting accuracy of human ‘predators’ in virtual reality. Next, I examined the
concept of ‘protean insurance’ via digitised movements of the painted lady butterfly,
exploring the qualities of this animals’ movement paths related to human targeting
ability. I then explored how the dynamics of animal groupings affected protean
movement. Specifically, I investigated how increasing movement path complexity
interacted with the well-documented ‘confusion effect’. I explored this question
using both an experimental study and a VR citizen science game disseminated to the
general public via the video game digital distribution service ‘Steam’. Subsequently,
I explored another phenomenon associated with groupings of prey items; the ‘oddity
effect’, which describes the preferential targeting of phenotypically odd individuals
by predators. Typically, this phenomenon is associated with oddity of colouration or
size. In this case, I investigated whether oddity of protean movement patterns
relative to other group members could induce a ‘behavioural oddity effect’. Finally, I
used a specialised genetic algorithm (GA) that was driven by human performance
with respect to targeting prey items. I investigated the emergent protean movement
paths that resulted from sustained predation pressure from humans. Specifically, I
examined the qualities of the most fit movement paths with respect to control
evolutions that were not under the selection pressure of human performance
(randomised evolution). In the course of this thesis, I have gained a deeper
understanding of a near ubiquitous component of predator prey interactions that
has until recently been the subject of little empirical study. These findings provide
important insights into the understudied phenomenon of protean movement, which
are directly applicable to predator –prey dynamics within a broad range of taxa
