Inbreeding Depression Increases Susceptibility to Bovine Tuberculosis in Lions: An Experimental Test Using an Inbred–outbred Contrast Through Translocation

Abstract

ABSTRACT:Disease can dramatically influence the dynamics of endangered wildlife populations, especially when they are small and isolated, with increased risk of inbreeding. In HluhluweiMfolozi Park (HiP), a small, enclosed reserve in South Africa, a large lion (Panthera leo) population arose from a small founder group in the 1960s and started showing conspicuous signs of inbreeding. To restore the health status of the HiP lion population, outbred lions were translocated into the existing population. In this study, we determined the susceptibility to bovine tuberculosis (bTB), and the prevalence of antibody to feline viruses of native lions, and compared the findings with those from translocated outbred lions and their offspring. Antibodies to feline herpesvirus, feline calicivirus, feline parvovirus, and feline coronavirus were present in the lion population, but there was no significant difference in antibody prevalence between native and translocated lions and their offspring, and these feline viruses did not appear to have an effect on the clinical health of HiP lions. However, feline immunodeficiency virus (FIV), which was previously absent from HiP, appears to have been introduced into the lion population through translocation. Within 7 yr, the prevalence of antibody to FIV increased up to 42%. Bovine tuberculosis posed a major threat to the inbred native lion population, but not to translocated lions and their offspring. More than 30% of the native lion population died from bTB or malnutrition compared with ,2% of the translocated lions and their offspring. We have demonstrated that management of population genetics through supplementation can successfully combat a disease that threatens population persistence. However, great care must be taken not to introduce new diseases into populations through translocation.

Walking with lions: why there is no role for captive-origin lions Panthera leo in species restoration

“…The disease is poorly understood in lions but is believed to contribute to poor health in extreme cases. Thirty percent of the severely inbred Hluhluwe-iMfolozi lion population died from bTB (combined with malnutrition) in 2000-2009, although , 2% of outbred lions translocated into this population were affected in the same period (Trinkel et al, 2011). Similarly, the effect was considered negligible in the outbred population in Kruger (Ferreira & Funston, 2010).…”

“…FIV-positive Hluhluwe-iMfolozi lions were apparently unaffected despite recent exposure to the virus and significant inbreeding depression that could be expected to elevate vulnerability (Trinkel et al, 2011). Despite the lack of disease the presence of FIV is employed as an argument for preferring captive, FIV-negative animals (Guo, 2009).…”

“…CDV generally lacks clinical signs or measurable mortality in lions, and previous CDV events in that population were relatively innocuous (Packer et al, 1999). Other pathogens such as feline herpes virus, feline calicivirus, feline parvovirus and coronavirus are widespread in lions but rarely cause illness (Spencer 1992;Packer et al, 1999;Trinkel et al, 2011).…”

“…Additionally, introduction of novel pathogens by captive animals could be catastrophic to wild populations (Daszak et al, 2000). Captive-bred carnivores are exposed to an unnatural variety of pathogens from close contact with other captive species and humans (Williams & Thorne, 1996, Martella et al, 2007 yet they can only be screened for a limited number of wellknown diseases (and screening may fail; Trinkel et al, 2011).…”

Mycobacterium bovis infection in the lion (Panthera leo): Current knowledge, conundrums and research challenges

“…common duiker (Sylvicapra grimmia), eland (Taurotragus oryx), honey badger (Mellivora capensis), impala (Aepyceros melampus), large spotted genet (Genetta tigrina), leopard (Panthera pardus), lechwe (Kobus leche), lion (Panthera leo), spotted hyaena (Crocuta crocuta), and warthog (Phacochoerus aethiopicus) (Keet et al 1996;de Vos et al 2001;Cleaveland et al 2005;Michel et al 2006;Trinkel et al 2011;OIE, 2012). All species do not appear to have the same susceptibility to infection with M. bovis and their role in the epidemiology can be roughly grouped into spillover hosts and maintenance hosts (Ayele et al 2004).…”