Ticks, vectors of numerous pathogens, are of primary importance in animal and human health. Understanding the factors explaining their distribution is a pre-requisite for the study of the diseases they transmit. The role of biotic interactions such as competition between tick species has been poorly studied. Our objective is to assess the role of interspecific competition in the delimitation of the range limits of A. variegatum and A. hebraeum, two ticks of veterinary importance in south-east Africa having a parapatric distribution. A survey was conducted in Mozambique to better assess the relative distribution of the two species and the degree of their interactions. Habitat suitability was predicted for both species, using the environmental niche model Maxent. Our results showed that co-occurrences in the field were rare. Few areas of sympatry were predicted by the environmental niche models. In view of these results, the relative contribution of environment and interspecific competition to the delimitation of the parapatric boundary between A. variegatum and A. hebraeum is discussed.