Temporal patterns of reproduction in ungulates of Tsavo East National Park, Kenya

Summary Temporal patterns of reproduction in nine species of ungulates were studied by means of repeated road strip counts and through observation of individually known females. Zebra and oryx show one distinct peak of births annually, Coke's hartebeest two peaks per year, but all these species may give birth throughout the year. In waterbuck, impala, Grant's gazelle, gerenuk, lesser kudu and giraffe no marked peaks were evident, i.e. reproduction is largely non‐seasonal. Only the warthog (though not studied in detail) has a short, distinct reproductive season. While mean rainfall and temperatures follow a well‐defined seasonal pattern, rainfall is often irregularly distributed, both in time and in space, and varies considerably from year to year. For most species, more or less continuous reproduction may therefore be more advantageous than a seasonal pattern related to average climatic conditions. Other factors influencing the temporal pattern of reproduction include phylogenetic relationships and food habits. Seasonal reproduction is more marked in grazers than in browsers, and this difference is probably related to seasonal changes in food quality.