Epidemiology of an intestinal parasite (Spirometra spp.) in two populations of African lions (Panthera leo)

Infection with the cestode Spirometra spp. was studied in 2 populations of lions in the Serengeti and the Ngorongoro Crater in Tanzania, East Africa. These 2 lion populations lived in different habitats and were known to diff er genetically: lions in the Serengeti were outbred, whereas lions in the N gorongoro Crater were inbred. Faecal samples were collected from 112 indivi dually known lions between March 1991 and November 1992. Over 60 %, of lion s were infected and the median intensity of infection was 975 eggs per g of faeces. The distribution of egg counts was overdispersed. There was variab ility through time, though this was unrelated to seasons delimited by rainf all. There were no significant differences in levels of infection between a ge classes; cubs less than 9 months were already heavily infected. Sex and reproductive status did not have a significant effect. However, there were significant differences in intensities of infection between the Crater and the Serengeti populations - Spirometra spp. showed a higher level of infect ion intensity in the Crater population - with some variation between prides within these populations. Allozyme heterozygosity scores were available fo r a subset of 28 lions but were unrelated to levels of Spirometra infection . It was not possible to ascribe differences in levels of parasite infectio n to genetic rather than ecological factors.