Texas tortoise task force: Collaborative networks to increase surveillance of disease in tortoises




Tleimat, Jacquelyn
McCracken, Shawn

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Texas tortoises are the only North American tortoise not receiving federal protection and due to life history traits of low fecundity and limited dispersal they are particularly susceptible to anthropogenically-mediated decline, such as the oil and gas exploration throughout their range. Not only do these disturbances fragment the habitat of the Texas tortoise and restrict their range, but they may also suppress immune function increasing their susceptibility to disease. Upper respiratory tract disease (URTD) has been detected in all desert tortoise species and may cause morbidity and mortality in infected individuals. However, there is limited data on the presence of URTD in Texas tortoises and whether anthropogenic stressors or biological factors influence disease dynamics, hindering development of informed management strategies and actions. Therefore, we propose to 1) test for presence of URTD casual agents across the range of the Texas tortoise in the U.S.A. and 2) assess whether tortoises are more susceptible to URTD based on biological characteristics and anthropogenic stressors. To ensure our survey efforts are as widely representative as possible, we have established a network of biologists and citizen scientists to aid in our efforts. We have created an outreach and communication system with protocols for submitting observation data and assistance with obtaining biological samples. We will collect blood samples from Texas tortoises and send plasma samples to test for both URTD causal agents (Mycoplasma agasizzi and M. testudineum). We will further collect geographic variables, such as distances to oil/gas operations and distances to road, biological data (age, sex, size, any clinical URTD signs) to understand if certain anthropogenic stressors increase the prevalence of URTD. This knowledge will aid in relocation efforts of Texas tortoises in proximity to oil/gas operations and increase our understanding of disease prevalence in the species.



testudines, disease ecology, mycoplasmosis, gopherus berlandieri



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