Trade-off between resource seasonality and predation risk explains reproductive chronology in impala

摘要: We investigated the variation in birth synchrony displayed by impala Aepyceros melampus populations across their distribution from southern to eastern Africa. Our analysis was based on field data Chobe National Park Botswana and Mala Private Game Reserve South Africa (4 13 years of monitoring, respectively). compared our results with those other studies conducted species range. Impala lambing highly synchronized 90% lambs born within 2 weeks mid-November. Variation rainfall preceding wet season explained 74% dates first lamb observation Mala. In Chobe, earliest peak occurred after highest body condition that cohort also best for both males females. No association found between lunar cycle estimated onset conception period, despite previous having an rutting behaviour males. On a regional scale, impalas areas marked dry (several months no rain) tend synchronize births rains, when grass quality is highest. Number rain 78% synchrony. Neither latitude nor total contributed significantly stepwise multiple regression model. These support theory seasonal food supply, temporally space less (equatorial) reduce predation risks.