A Bayesian approach to modelling field data on multi-species predator prey-interactions

Bayesian statistical decision theory;Circus cyaneus;Harp seal;Predation (Biology)--Mathematical models

Asseburg, Christian ; Harwood, John ; Harwood, John

University:University of St Andrews

Department:Research Centres and Institutes

关键词: Bayesian statistical decision theory;    Circus cyaneus;    Harp seal;    Predation (Biology)--Mathematical models;   

Others  :  https://research-repository.st-andrews.ac.uk/bitstream/handle/10023/174/ChristianAsseburgPhDThesis.pdf?sequence=6&isAllowed=y

来源: DR-NTU

【 摘 要 】

Multi-species functional response models are required to model the predation of generalist preda-tors, which consume more than one prey species. In chapter 2, a new model for the multi-speciesfunctional response is presented. This model can describe generalist predators that exhibit func-tional responses of Holling type II to some of their prey and of type III to other prey. In chapter3, I review some of the theoretical distinctions between Bayesian and frequentist statistics andshow how Bayesian statistics are particularly well-suited for the fitting of functional responsemodels because uncertainty can be represented comprehensively. In chapters 4 and 5, the multi-species functional response model is fitted to field data on two generalist predators: the henharrier Circus cyaneus and the harp seal Phoca groenlandica. I am not aware of any previousBayesian model of the multi-species functional response that has been fitted to field data.The hen harrier's functional response fitted in chapter 4 is strongly sigmoidal to the densitiesof red grouse Lagopus lagopus scoticus, but no type III shape was detected in the response tothe two main prey species, field vole Microtus agrestis and meadow pipit Anthus pratensis. Theimpact of using Bayesian or frequentist models on the resulting functional response is discussed.In chapter 5, no functional response could be fitted to the data on harp seal predation. Possiblereasons are discussed, including poor data quality or a lack of relevance of the available data forinforming a behavioural functional response model.I conclude with a comparison of the role that functional responses play in behavioural, populationand community ecology and emphasise the need for further research into unifying these differentapproaches to understanding predation with particular reference to predator movement.In an appendix, I evaluate the possibility of using a functional response for inferring the abun-dances of prey species from performance indicators of generalist predators feeding on these prey.I argue that this approach may be futile in general, because a generalist predator's energy intakedoes not depend on the density of any single of its prey, so that the possibly unknown densitiesof all prey need to be taken into account.