Defending Wild Dogs: Population Dynamics and Disease in Endangered African Wild Dogs

摘要

African wild dogs (Lycaon pictus) are endangered carnivores whose population is decreasing from habitat loss and fragmentation, interspecific competition, and disease. Survival rates are especially low in Kruger National Park (KNP), though it is unclear why. I estimated the abundance in KNP and survival rates over different time spans, six years and nine months, using public photographic survey data. In 2015, there were 298 (SE=12.1) individuals. Using a mark-recapture analysis in program R, I found that the survival rate between 2009-2015 was only 3.2%, and within the 9-month survey period (September 2014 -- June 2015), monthly survival rates for the wild dogs varied by region of the park, with apparent survival (ϕ) at 0.807 (0.695-0.885 95%CI), 0.989 (0.852-0.999), and 0.975 (0.946-0.989) for dogs in the northern, central, and southern region of the park, respectively. I estimated mean lifespan to be .39 years, 7.2 years, and 3.3 years for the northern, central, and southern regions, respectively, and 1.41 years for all dogs combined. Recapture probability for the dogs varied by region and month, ranging between 0.07 and 0.828, highest in the south, followed by the north, then the central region, with an overall monthly recapture probability average in the park of 0.483 (SE=0.0148). Because disease is becoming an increasing threat to wild dogs and other wild canids, I also conducted review of the disease prevalence and vaccination strategy and efficacy in African wild dogs and Ethiopian wolves, focused on canine distemper and rabies. I found that vaccination with modified-live or recombinant vaccines, including annual boosters will be a key strategy in disease management going forwards. Vaccination of domestic dogs near wolf and wild dog populations, vaccination of wolves and wild dogs themselves, and a combination of the two, all appear to be viable management strategies in different scenarios. A greater understanding of population dynamics and disease dynamics from this study, in addition to more intensive population and disease monitoring in the future, will help provide necessary information to guide successful management strategies of these two critically endangered species, and specifically wild dogs in Kruger National Park.