Does bird life-history influence the prevalence of ticks? A citizen science study in North East Spain

Abstract

After mosquitoes, ticks are among the most important vector of pathogens of concern for animal and public health, but unless mosquitoes ticks remain attached to their hosts for long time periods providing an opportunity to analyse their role in the dispersal and dynamics of different zoonotic pathogens. Given their interest in public health it is important to understand which factors affect their incidence in different hosts and to stablish effective surveillance programs to determine the risk of transmission and spill-over of zoonotic pathogens. Taking benefit of a large network of volunteer ornithologists, we analysed the life-history traits associated to the presence of ticks using information of 620,609 individuals of 231 avian species. Bird phylogeny, locality and year explained a large amount of variance in tick prevalence. Non-colonial species non breeding in grasslands and non-spending the non-breeding season as gregarious groups or isolated individuals (e.g. thrushes, quails and finches) had the higher prevalence of ticks and appear as good candidates for zoonosis surveillance programs based on the analyses of ticks collected from wild birds. Ringers underestimated tick prevalence but can be considered as an important source of information of ticks for public and animal health surveillance programs if properly trained for the detection and collection of the different tick development phases.

Keywords: Gregariousness; Host-pathogen interactions; Long distance dispersal; Long-term study; Migrant birds; Parasite incidence; Tick prevalence.

Fig. 1

Posterior mean estimates and 95% credible intervals of fixed effects predictors of the probability of being infested by ticks when phylogeny is included in the model as a random factor. Intercept were removed for visualisation.

Fig. 2

Phylogenetic tree of the species analysed together with a bar with the relative prevalence detected for each species. Each bar represents the relative tick prevalence per taxa (maximum = 0,03% for Turdus iliacus, see Supplementary Table for all the prevalences).

Fig. 3

Posterior mean estimates and 95% credible intervals of fixed effects predictors of the probability of being infested by ticks when phylogeny is not included as a random factor. Parameters with intervals that do not overlap zero are considered to have a significant influence on the response and are plotted in red. Intercept were removed for visualisation. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)