Grooming Behaviour and Parasite Load in the Greater Horseshoe Bat

Abstract

Among the findings in this study was that allo-grooming does not occur between adult bats. Even though R. ferrumequinum forms long-term roost societies these groups are not really closed. Female bats immigrate to and emigrate from the colony and this could perhaps prevent co-operative behaviour developing like social-grooming between adults because reciprocity is not ensured.It was also found that age of offspring was related to the amount of time lactating females groomed their offspring, although there was no effect on the time lactating bats dedicated to grooming themselves. E. euryalis infestation levels always were at considerably low levels.The main hosts were young juveniles and their mothers. The parasite load of mother and offspring correlated positively. There is some evidence that lifecycles may be synchronised in this parasite-host-community. Juvenile parasite load decreased when lactation ended and younger juveniles always carried more parasites than the other bats in the roost.This difference vanished when juveniles grew older. Lactating bats were always more infested with mites than non-breeding females. This findings suggest that the close physical contact between mother and offspring seems to be an in important part in the mites lifecycle and that vertical transmission occurs at substantial levels in these this mites. Infestation on adult males was always considerably lower than other bat groups.Adult males are usually solitary and therefore are unlikely to be infested. I found no evidence that E. euryalis harmed its host R. ferrumequinum: Infestation with E. euryalis had no impact on the survival rate of juveniles. In addition to this I found no correlation between body condition and parasite load. In juvenile bats it seemed that bats in average condition were more likely to have high infestation levels of mites than bats in very good or very poor condition.The results on the impact of grooming on parasite infestation are controversial.