Ecological and Competitive Relations Among Three Species of Frogs (Genus Rana)

摘要: Interspecific competition is often advanced as an explanation for replacement of species by ecological counterparts. Where environments are stable, in controlled laboratory experiments, interspecific usually leads to the extinction one species. In a complex natural environment, fluctuations physical and biotic factors may long delay competitive exclusion. The existence three related frogs (genus Rama) confined stream tropical rain forest provided opportunity manipulate populations thus study relation between overlap niches competition. A area was chosen because it lacks significant seasonal variation rainfall, temperature, photo—period consequently prevents specialization fauna. These species, R. blythi, ibanorum, macrodon, proved be very similar habits. Rana blythi larger than other two found farther from bed. macrodon reaches sexual maturity faster others ibanorum lays fewer eggs. Nonetheless clear that their extensively. Populations these were studied on surveyed portions streams mark release techniques. (Sungei Ensurai) another Sekentut) initially much smaller respective streams. Following removal Sungei Sekentut Ensurai, leaving Serbong controls, Ensurai appeared almost double numbers reach population levels originally Population estimates ibanourm fluctuated, being at midyear; statistical support this weak. seemed quadruple its Sunge Sekentut. There evidence process invading part Borneo doing so expense ibanorum. Maximum fixed intraspecific competition, which turn responsible maintaining coexistence