Plague, Wildlife Disease and Contact Networks

Please note time is AEDT

Seminar Abstract:

Great gerbils are desert rodents inhabiting vast areas of central Asia. As the main reservoir host of plague (flea-borne Yersinia pestis infection) they play a central role in many of the plague foci in this region. The results of modelling this system – in a way that brings together the three spatial scales of the landscape, the flea movements responsible for transmission of plague and the scale at which plague surveillance is carried out – suggest that the spread of Yersinia pestis among great gerbils (Rhombomys opimus) is a vast, natural percolation process, and that there is a percolation threshold in terms of the fraction of burrow systems inhabited. This older work has prompted more recent related work using 7 years of mark-recapture data from field voles to construct spatial contact networks, and to then measure how spatial they are. To do this we (i) fit statistical models to the edge data and (ii) propose a graph dissimilarity measure. When we apply these methods to the vole data we find that the topology of the vole contact networks changes as population density varies in several ways; they become more spatial and more predictable, and while the average degree increases the heterogeneity in degree becomes lower. The net effect of these changes may be part of the explanation for why sharp abundance thresholds for wildlife disease are so rarely detected in nature.

Host University: RMIT University

Seminar Convener: Stelios Georgiou

How to participate in this seminar

1. Book your University’s Access Grid Room, or a university or APAC etc. Access Grid Room that you are able to use, and

2. Send an email to the seminar convenor at RMIT University (Stelios Georgiou) to advise that you will be attending the seminar.