Effects of maternal parasite load on offspring life-history traits in the common lizard (Lacerta vivipara)

We studied the effect of maternal ectoparasite load (measured at parturition) on the life-history traits of the offspring of the host Lacerta vivipara, the European common lizard. The ectoparasite, a mite belonging to the family Laelapidae, had a detrimental effect on its host: parasite load was associated with increased host mortality, and was negatively correlated with host body mass. Parasite load was persistent over time, suggesting that parasite load can be predictable. Offspring of highly parasitised mothers had higher values of several fitness components early in life than offspring of parasite-free mothers or lightly infested mothers. This was expressed in terms of increased F-1 yearling growth rate, and reproductive investment at first reproduction (measured as F-2 hatchling mass). These results are interpreted as a host adaptation to attenuate the impact of parasites. Indeed, if high parasite loads arise from long exposure time to a constant population of parasites, and if the negative effects of parasites are additive over time, hosts could reduce the impact of parasites simply by investing more during the earlier stages of life. Naturally, having better performance early in life should lead to higher mortality rates and/or lower fecundity later in life.