Rabbits, stoats and the predator problem: Why a strong animal rights position need not call for human intervention to protect prey from predators

Animal rights positions face the ‘predator problem’: the suggestion that if the rights of nonhuman animals are to be protected, then we are obliged to interfere in natural ecosystems to protect prey from predators. Generally, rather than embracing this conclusion, animal ethicists have rejected it, basing this objection on a number of different arguments. This paper considers but challenges three such arguments, before defending a fourth possibility. Rejected are Peter Singer’s suggestion that interference will lead to more harm than good, Sue Donaldson and Will Kymlicka’s suggestion that respect for nonhuman sovereignty necessitates non-interference in normal circumstances, and Alasdair Cochrane’s solution based on the claim that predators cannot survive without killing prey. The possibility defended builds upon Tom Regan’s suggestion that predators, as moral patients but not moral agents, cannot violate the rights of their prey, and so the rights of the prey, while they do exist, do not call for intervention. This idea is developed by a consideration of how moral agents can be more or less responsible for a given event, and defended against criticisms offered by thinkers including Alasdair Cochrane and Dale Jamieson.

Multiple robots formation manoeuvring and collision avoidance strategy

This paper presents a multiple robots formation manoeuvring and its collision avoidance strategy. The direction priority sequential selection algorithm is employed to achieve the raw path, and a new algorithm is then proposed to calculate the turning compliant waypoints supporting the multi-robot formation manoeuvre. The collision avoidance strategy based on the formation control is presented to translate the collision avoidance problem into the stability problem of the formation. The extension-decomposition-aggregation scheme is next applied to solve the formation control problem and subsequently achieve the collision avoidance during the formation manoeuvre. Simulation study finally shows that the collision avoidance problem can be conveniently solved if the stability of the constructed formation including unidentified objects can be satisfied.

No discrimination shock avoidance with sequential presentation of stimuli but shore crabs still reduce shock exposure

Insights into the potential for pain may be obtained from examination of behavioural responses to noxious stimuli. In particular, prolonged responses coupled with long-term motivational change and avoidance learning cannot be explained by nociceptive reflex but are consistent with the idea of pain. Here, we placed shore crabs alternately in two halves of a test area divided by an opaque partition. Each area had a dark shelter and in one repeated small electric shocks were delivered in an experimental but not in a control group. Crabs showed no specific avoidance of the shock shelter either during these trials or in a subsequent test in which both were offered simultaneously; however they often emerged from the shock shelter during a trial and thus avoided further shock. More crabs emerged in later trials and took less time to emerge than in early trials. Thus, despite the lack of discrimination learning between the two shelters they used other tactics to markedly reduce the amount of shock received. We note that a previous experiment using simultaneous presentation of two shelters demonstrated rapid discrimination and avoidance learning but the paradigm of sequential presentation appears to prevent this. Nevertheless, the data show clearly that the shock is aversive and tactics, other than discrimination learning, are used to avoid it. Thus, the behaviour is only partially consistent with the idea of pain.