Seasonality in spatial organization and dispersal of sympatric jackals (Canis mesomelas and C. adustus): Implications for rabies management

In Zimbabwe the incidence of reported jackal rabies varies predictably over the year with peaks during June to August (cold dry season) and December to May (wet season), and may be explained by the social behaviour of jackals. June to August is the mating season, at which time home ranges increase in size, and overlap between species and neighbouring conspecifics is greater. Intra-group concordance in range use decreases in association with the social stress caused by mating and mate guarding, and young adults use peripheral areas, perhaps increasing contact with neighbouring jackals. Dispersal is most likely to occur in the mating season. These factors increase the contact rate between neighbours and, therefore, rabies incidence. In the hot dry season (the whelping season), home ranges decrease in size, and the overlap of interspecific and neighbouring conspecific ranges decreases. Concordance in range use of intra-group conspecifics increases and activity focuses on the den; inter-group contact rate therefore decreases, as does rabies incidence. The addition of juveniles to the population in the wet season increases jackal density and thus contact rate and also coincides with a high rabies incidence. Taking these factors into account, we suggest that the control of jackal rabies by oral vaccination should focus on the period before the mating season and after the whelping season.