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

Pablo M. Beldomenico, Sandra Elizabeth Telfer, Stephanie Gebert, Lukasz Lukomski, Malcolm Bennett, Michael Begon

Research output: Contribution to journalArticle

64 Citations (Scopus)

Abstract

1. Pathogens have been proposed as potentially important drivers of population dynamics, but while a few studies have investigated the impact of specific pathogens, the wealth of information provided by general indices of health has hardly been exploited. By evaluating haematological parameters in wild populations, our knowledge of the dynamics of health and infection may be better understood.

2. Here, haematological dynamics in natural populations of field voles are investigated to determine environmental and host factors associated with indicators of inflammatory response (counts of monocytes and neutrophils) and of condition: measures of immunological investment (lymphocyte counts) and aerobic capacity (red blood cell counts).

3. Individuals from three field vole populations were sampled monthly for 2 years. Comparisons with individuals kept under controlled conditions facilitated interpretation of field data. Mixed effects models were developed for each cell type to evaluate separately the effects of various factors on post-juvenile voles and mature breeding females.

4. There were three well-characterized 'physiological' seasons. The immunological investment appeared lowest in winter (lowest lymphocyte counts), but red blood cells were at their highest levels and indices of inflammatory response at their lowest. Spring was characterized by a fall in red blood cell counts and peaks in indicators of inflammatory response. During the course of summer-autumn, red blood cell counts recovered, the immunological investment increased and the indicators of inflammatory response decreased.

5. Poor body condition appeared to affect the inflammatory response (lower neutrophil and monocyte peaks) and the immunological investment (lower lymphocyte counts), providing evidence that the capacity to fight infection is dependent upon host condition.

6. Breeding early in the year was most likely in females in better condition (high lymphocyte and red blood cell counts).

7. All the haematological parameters were affected adversely by high population densities.

Original languageEnglish
Pages (from-to)984-997
Number of pages14
JournalJournal of Animal Ecology
Volume77
Issue number5
Early online date28 Jun 2008
DOIs
Publication statusPublished - Sep 2008

Keywords

  • haematology
  • Microtus agrestis
  • population dynamics
  • wildlife health
  • microtus-agrestis populations
  • cowpox virus-infection
  • trade-offs
  • survival
  • winter
  • immunology
  • dependence
  • decreases
  • predation
  • ecology

Cite this