The effects of host and environmental factors on tick parasitism in red deer are modulated by sex

Póster presentado al Joint 8th International Ticks and Tick-borne Pathogens and 12th Biennial Society for Tropical Veterinary Medicine Conference, celebradas en Cape Town (Sudafrica) del 24 al 29 de agosto de 2014.[Objectives]: Host individual, host population and environmental factors interact to modulate parasite abundance in hosts. Since size dimorphism, life history traits and segregation observed in red deer (Cervus elaphus) are linked to sex and this ungulate species constitutes a highly relevant host for adult exophilic ticks, it was hypothesized that tick parasitism on stags and hinds would be differentially influenced by each of these factors. [Method]: Ticks from 306 red deer were collected during 7 years in a red deer population. By generalized linear models we modelled tick abundance on deer with 20 potential predictors. Three models were developed: one for stags, another for hinds, and one combining data from both sexes and including >sex> as factor. Our rationale was that if tick burdens on males and hinds relate to the explanatory factors in a differential way, it is not possible to precisely and accurately predict the tick burden on one sex using the model fitted on the other sex, or with the model that combines data from both sexes. Our results showed that deer males were the primary target for ticks, the weight of each factor differed between sexes, and each sex specific model was not able to accurately predict burdens on the animals of the other sex. [Conclusions]: Results support for sex-biased differences in tick parasitism in red deer. The higher weight of host individual and population factors in the model for stags show that intrinsic deer factors more strongly explain tick burden than environmental host-seeking tick abundance. In contrast, environmental variables better explained tick burdens in hinds.We thank gamekeepers, project AGL2010‐20730‐C02 (Spanish Ministry for Economy and Competitiveness‐MINECO) and EU FP7 grant ANTIGONE (278976). F. Ruiz‐Fons & P. Acevedo are supported by MINECO.Peer Reviewe