Macroparasites in general, and ectoparasites in particular, have the potential to regulate host population dynamics. In this context, this study addresses the tick parasitism traits of the Mediterranean spur-thighed tortoise (Testudo graeca) in the core area of its distribution range (northwestern Morocco, Maamora). It was discovered that 92.5% of the tortoises were parasitized by ticks in spring, with an infestation intensity and an abundance of 6.7 and 6.2 tick/tortoise, respectively. The observed parasitization rates were among the highest reported worldwide for T. graeca, which could relate to density-depended effects driving host-parasite interactions. The main tick species that parasitized the tortoises were Hyalomma aegyptium (95.6% of the ticks and in the 100% of the parasitized tortoises), Hy. marginatum, Hy. excavatum and Hy. scupense. Individual predictors for the tortoises, such as age, sex and the interaction between body condition and sex, were significantly related to tick abundance. Age-related behavioural differences might favour a higher host-tick effective contact in adults than in juveniles. The fact that males are more active in spring - the breeding season - might explain the observed male bias in tick abundance and may also be responsible for the negative effect of male body condition on tick infestation rate in contrast to females. Given the potential role played by parasites as regards modulating population dynamics, our results suggest that ticks should be taken into account in the conservation and management programmes of this tortoise species.
Reference: A Segura, O Rodríguez, F. Ruiz-Fons, P. Acevedo. Tick parasitism in the Mediterranean spur-thighed tortoise in the Maamora forest, Morocco. Ticks and Tick-borne Diseases, in press https://doi.org/10.1016/j.ttbdis.2018.11.002