Abstract:
Before commencing to write this paper, it was realized only too fully that any check list or host list of the external parasites occurring on South African mammals, birds, and reptiles written at the present time would be very far from being complete. It was, however, considered advisable to place on record our present knowledge of these parasites, not only with a view to bringing it up to date as far as possible, but also to encourage the collection of parasites by zoologists, ornithologists, and others, who periodically have grand opportunities of obtaining material. Every year the country is being thrown open more extensively to settlers and, as civilization advances, wild animals and birds decrease in numbers. It is quite possible that within a short period some of our mammals and birds may become extinct – if not altogether, certainly in some districts – and it would be very interesting and important to have a knowledge of the parasites before their hosts disappear, and they with them. The distribution of a permanent parasite, i.e. a parasite which is entirely dependent upon its host for its existence, such as a bird-louse or parasitic mite, usually coincides with the distribution of its host, or may, if it possesses more than one host, as is frequently the case, overlap it. For instance, both the bird-louse (Esthiopterum struthionis) and the feather mite (Pterolichus bicaudatus) of the South African ostrich have also been found on the American ostrich (Rhea americana), and the former has also been recorded from the North African ostrich (Struthio camelus). On the other hand, parasites, such as ticks, fleas, and some parasitic mites, which do not live the whole of their existence on their hosts, are usually restricted in their range, owing to climatic conditions, unfavourable breeding grounds, etc. Temporary parasites are, as a rule, less particular in the selection of their hosts than are permanent parasites, and many of them may be found on a number of animals which are in no way related to each other. Therefore, the distribution of a temporary parasite may also overlap the distribution of some of its hosts. In this paper I have not hesitated to include all permanent parasites found on migratory birds, irrespective of whether the parasites were collected in this country or not, except that American records have not been included, because, as a rule, most birds migrate from north to south or vice versa. In every instance where the parasite has been collected in this country the locality has been given. On the other hand, only temporary parasites have been included when they have been actually found or recorded as taken in South Africa.