The spatial agent-based model OHDEAR: Effects of predation and disturbance on forager groups

Activiteit: Academic presentationAcademic


Group living is of benefit to foraging individuals by improving their survival, through passive risk dilution by sheer numbers and through increasingly more active processes, ranging from cue transmission to alarm calling. Focusing on the lower end of this range: An involuntary visual cue can be given by a fleeing action, and lead to cue transmission of information within a group. This model is a bottom-up model of foragers as agents with embodiment in a simple environment, where only assumptions about basic competences for living are made, valid for a wide group of species.
We use an agent-based and spatially explicit model to investigate the effect of disturbance by predators (always fleeing is the appropriate reaction) and, to make the model more realistic, added harmless passers-by, that now cause false fleeing. We set out to investigate whether adaptive behaviour could improve outcomes: We investigated whether two very common subconscious behaviours can mitigate the detrimental effects of false fleeing. The first is “experience gain”, an experiential change, the second is “fear updating”, an emotional change.
To implement these behaviours we needed to: 1) define better the anti-predator behaviour chain: “detection, recognition, and response”. 2) how to deal with the combined probabilities of the detection- and recognition sigmoids. We added three fear levels: one each for predator and passer-by and one for the environment, as base for response when detection without recognition occurred. 3) the initial levels for these behaviours had to be defined.
These modelling decisions are shown to be very important. HIREC situations with new predators or with newly released groups can be mapped to these initial settings: does the forager group meet a familiar predator type or a novel one for instance, giving insight into what is most important for forager groups.
EvenementstitelDutch Society for Theoretical Biology (NVTB) Annual Meeting 2024
LocatieSchoorl, NetherlandsToon op kaart
Mate van erkenningNational