Removal of Capybara (Hydrochoerus hydrochaeris) population as measure to control Amblyomma tick population and reduce Brazilian Spotted Fever transmission risk in a Gated Community in Bragança Paulista (SP, Brazil) – Case Study

Abstract

This study reports the factors which led a gated community located in Bragança Paulista (SP, Brazil), a non-endemic area for Brazilian Spotted Fever (BSF), to be classified as a Risk Area for transmission of this disease, showing that an increasing resident population of capybaras (Hydrochoerus hydrochaeris) in the area was likely responsible for a proliferation of Amblyomma sculptum ticks and acted as an amplifying host for Rickettsia rickettsii, the main etiologic agent of BSF. We report management actions proposed to control the local tick burden and reduce BSF risk, including measures to control parasitic and free-living tick populations and exclusion of the resident capybara population. Analyses of tick population data and R. rickettsii serology tests indicate that these measures were effective, greatly reducing the environmental burden of Amblyomma sculptum ticks and reducing the BSF transmission risk at the area.

Positive-reinforcement strategies to reduce capture-stress in Capybaras

“…To evaluate the success of our strategies in reducing capture and handling associated stress, we focused on direct behavioral observations (Skinner, 1938;Aguiar & Moro-Rios, 2009), such as conduct, body language, and vocalization. Capybaras have a broad spectrum of vocal communication (Sánchez, 2003;Barros, Tokumaru, Pedroza, & Nogueira, 2011;personal communication, 2017/2018. Interpretations were done by one observer and were based on vocal (V) and body language (BL) expressions for an individual's, and group's emotional state, discriminating between three principal states: (1) general well-being, curiosity, and positive excitement (V: high-pitched purring-clicking, often contagious to the rest of the group.…”

“…The literature describing detailed capture methods for capybaras is limited and the few studies that are available are not suitable for an English-speaking audience. However, capture methods can be divided into three groups: (1) lassoing, a traditional method commonly employed by Argentinian cowboys ( (Souza et al, 2008;Moreira et al, 2013;Kuniy et al, 2018). The first two methods can potentially provoke intense stress and have an increased risk of injury or death and would make recapture almost impossible.…”