Merino, Karakul, Dorper, Blackhead Persian and Namaqua Arikaner ewes were tested for oestrus twice daily over a period of six years to evaluate their reproductive patterns under the semi-arid conditions of the North Western Cape. It was found that the Merino and Karakul exhibited sexual activity from February to August and January to August respectively. In the case of the Namaqua Arikaner sexual activity was reduced during December only. The Blackhead-Persian exhibited cycles for a slightly shorter period but at a higher level than the Namaqua Afrikaner. Although the breeding season of the Dorper was of an intermediate type, this breed showed oestrous activity at the highest level of the five breeds evaluated. Except for the Namaqua Arikaner, sexual activity during the non-breeding season increased with age up to 108 months.