The Intestinal Eukaryotic and Bacterial Biome of Spotted Hyenas: The Impact of Social Status and Age on Diversity and Composition.

In mammals, two factors likely to affect the diversity and composition of intestinal bacteria (bacterial microbiome) and eukaryotes (eukaryome) are social status and age. In species in which social status determines access to resources, socially dominant animals maintain better immune processes and health status than subordinates. As high species diversity is an index of ecosystem health, the intestinal biome of healthier, socially dominant animals should be more diverse than those of subordinates.

Canine distemper virus in the Serengeti ecosystem: molecular adaptation to different carnivore species.

Was the 1993/1994 fatal canine distemper virus (CDV) epidemic in lions and spotted hyaenas in the Serengeti ecosystem caused by the recent spillover of a virulent domestic dog strain or one well adapted to these noncanids? We examine this question using sequence data from 13 'Serengeti' strains including five complete genomes obtained between 1993 and 2011. Phylogenetic and haplotype network analyses reveal that strains from noncanids during the epidemic were more closely related to each other than to those from domestic or wild canids. All noncanid 'Serengeti' strains during the epidemic encoded: (1) one novel substitution G134S in the CDV-V protein; and (2) the rare amino acid combination 519I/549H at two sites under positive selection in the region of the CDV-H protein that binds to SLAM (CD 150) host cell receptors.

The impact of a pathogenic bacterium on a social carnivore population.

1. The long-term ecological impact of pathogens on group-living, large mammal populations is largely unknown. We evaluated the impact of a pathogenic bacterium, Streptococcus equi ruminatorum, and other key ecological factors on the dynamics of the spotted hyena Crocuta crocuta population in the Ngorongoro Crater, Tanzania.

The fitness of dispersing spotted hyaena sons is influenced by maternal social status.

Life history theory predicts that mothers should provide their offspring with a privileged upbringing if this enhances their offspring's and their own fitness. In many mammals, high-ranking mothers provide their offspring with a privileged upbringing. Whether dispersing sons gain fitness benefits during adulthood from such privileges (a 'silver spoon' effect) has rarely been examined.

A Hepatozoon species genetically distinct from H. canis infecting spotted hyenas in the Serengeti ecosystem, Tanzania.

Health monitoring of spotted hyenas (Crocuta crocuta) in the Serengeti ecosystem, Tanzania, revealed Hepatozoon infection in all of 11 immature individuals examined following death from natural causes. Hepatozoon infection was probably an important factor contributing to mortality in two cases that exhibited clinical signs of ataxia, lethargy, ocular discharge, retching, and labored breathing before death. Whether Hepatozoon infection contributed to six deaths from fire, probable lion predation and unknown causes could not be determined.