Additional information about tick parasitism in Passeriformes birds in an Atlantic Forest in southeastern Brazil.

The habits of birds make them more or less susceptible to parasitism by certain tick species. Therefore, while some bird species are typically found to be intensely infested, others are relatively unaffected. This study investigated the occurrence of ticks in Passeriformes inhabiting an Atlantic Forest fragment in southeastern Brazil, during the dry and rainy seasons, by means of parasitological indexes and multiple correspondence analysis, to determine the factors that influence tick parasitism in these birds. Data were collected on 2391 ticks, all classified in the Amblyomma genus, from 589 birds. The ticks identified to the species level were A. longirostre, A. nodosum, A. calcaratum, A. parkeri, and A. ovale. Thamnophilidae, Conopophagidae, Thraupidae, Dendrocolaptidae, and Platyrinchidae were the families with the highest prevalence. In terms of parasite intensity, the families Conopophagidae, Thamnophilidae, Thraupidae, Furnariidae, and Pipridae stood out with the highest values. Bird species that are generalists regarding eating habits and habitat occupation tended to have higher parasite loads, as did larger species and those inhabiting the understory. The tick prevalence was higher in the dry season than in the rainy season. The majority of the ticks were collected from the head region, mainly around the eyes and in the nape. Also, this work reports 22 new bird-parasite relations.