The dynamics of health in field vole populations: a haematological perspective

BELDOMENICO PM; TELFER, S; GEBERT S; LUKOMSKI L; BENNETT M; BEGON M

Estes Park

Conferencia; 56th Annual Wildlife Disease Association Conference; 2007

Wildlife Disease Association

The periodic fluctuations of cyclic small mammal populations have puzzled biologists for decades. Pathogens have been suggested to be important drivers of population dynamics, but, although some studies investigated the impact of specific etiologic agents, those using generic indices of health to assess condition in an integrative manner have been rare. Hematological dynamics in natural populations of field voles were investigated to determine environmental and host factors associated with infection, immunocompetence and general condition. Three field vole populations were monthly sampled for two years, and on each trapping session, a blood specimen from every individual was processed to obtain a complete blood cell count. Also, samples from an experimental colony were analyzed, to reinforce the results and allow sounder conclusions. Sets of mixed effects models were developed for each main cell type to separately evaluate the effects of various factors on blood parameters of juveniles, post-juveniles, and mature breeding females. Season was the main driver of the dynamics of all cell types examined. In winter, voles appear vulnerable but infections do not occur. Spring, however, seems to be when voles are most at risk of disease, particularly at high past population densities