title: Biotic and abiotic predictors of tick (Dermacentor variabilis) abundance and engorgement on free-ranging raccoons (Procyon lotor).
abstract: We examined the relative importance of abiotic and biotic factors on the ability of adult Dermacentor variabilis ticks to attach and engorge with blood across 10 populations of free-ranging raccoons (Procyon lotor). We developed a priori models that represented explicit hypotheses based on the literature and tested the ability of these models to explain non-replete and replete (fully engorged with blood) tick infestation using generalized linear models and Akaike's Information Criterion. Abiotic models that included month and site of collection clearly provided a better fit for non-replete tick abundance data, while biotic models with host age and sex covariates best fit the replete tick data. Abiotic models of non-replete abundance were superior to biotic models because of large seasonal and site fluctuations in non-replete abundance that masked differences due to host characteristics. Conversely, best-fitting models of replete tick abundance included only age and sex and suggest that once a tick has reached a host, host-parasite interactions are the primary determinant of engorgement by female ticks. Host population structure may have a large influence on potential cohort size of ticks by reducing or increasing the total number and proportion that can become engorged and moult or lay eggs.
authors: Department of Fisheries and Wildlife Sciences, 302 Anheuser-Busch Natural Resources Building, University of Missouri, Columbia, MO 65211, USA. RyanMonello@mizzou.edu
authors: R J
authors: RJ
authors: Monello
authors: M E
authors: ME
authors: Gompper
mesh_terms: D000818:Animals; D001835:Body Weight; D003870:Dermacentor / Q000502:physiology*; D005247:Feeding Behavior; D005260:Female; D008297:Male; D011821:Raccoons / Q000469:parasitology*; D012307:Risk Factors; D012621:Seasons; D013984:Tick Infestations / Q000469:parasitology / Q000662:veterinary*