The distribution of parasites among hosts is often characterised by a high degree of heterogeneity with a small number of
hosts harbouring the majority of parasites. Such patterns of aggregation have been linked to variation in host exposure and
susceptibility as well as parasite traits and environmental factors. Host exposure and susceptibility may differ with sexes,
reproductive effort and group size. Furthermore, environmental factors may affect both the host and parasite directly and
contribute to temporal heterogeneities in parasite loads. We investigated the contributions of host and parasite traits as
well as season on parasite loads in highveld mole-rats (Cryptomys hottentotus pretoriae). This cooperative breeder exhibits a
reproductive division of labour and animals live in colonies of varying sizes that procreate seasonally. Mole-rats were
parasitised by lice, mites, cestodes and nematodes with mites (Androlaelaps sp.) and cestodes (Mathevotaenia sp.) being the
dominant ecto- and endoparasites, respectively. Sex and reproductive status contributed little to the observed parasite
prevalence and abundances possibly as a result of the shared burrow system. Clear seasonal patterns of parasite prevalence
and abundance emerged with peaks in summer for mites and in winter for cestodes. Group size correlated negatively with
mite abundance while it had no effect on cestode burdens and group membership affected infestation with both parasites.
We propose that the mode of transmission as well as social factors constrain parasite propagation generating parasite
patterns deviating from those commonly predicted.
Parasites deplete the resources of their host and can consequently affect the investment in competing traits (e.g.
reproduction and immune defence). The immunocompetence handicap hypothesis posits that testosterone (T) ...
Horak, Ivan Gerard; Chaparro, F.; Beaucournu, J-C.; Louw, J.P.; Verwoerd, Daniel Wynand(Published by the Agricultural Research Council, Onderstepoort Veterinary Institute, 1999)
Eighty yellow mongooses, Cynictis penicillata, from five localities in South Africa were examined for
arthropod parasites. Ten ixodid tick species, of which Haemaphysalis zumpti was the most abundant,
prevalent and widely ...