Odendaal F J, Bull C M
School of Biological Sciences, Flinders University, 5042, Bedford Park, South Australia.
Oecologia. 1983 Mar;57(3):361-367. doi: 10.1007/BF00377181.
Ranidella signifera and R. riparia are leptodactylid frogs with largely allopatric distributions which contact and narrowly overlap in the Flinders Ranges of South Australia. One hypothesisto explain the distributional limits is that each species cannot persist in the creeks beyond its range. Survival and growth of tadpoles were measured in enclosures in three creeks, one on either side of the overlap zone and one in it. When each species was kept alone there were no differences between them either in the slow water typical of R. signifera creeks or in fast moving water typical of R. riparia creeks. When the two species were kept together there were no consistent differences in survival or growth in any creek where water flow was shielded in the experimental enclosures. Where water flow was not shielded through the enclosures R. riparia tadpoles had significantly higher survival than R. signifera. A form of interaction is proposed where R. signifera is more frequently exposed to the water current when R. riparia is present. This may explain why R. signifera does not extend its distribution into the adjacent fast rocky creeks occupied by R. riparia, but the experiments did not explain the limitation of the range of R. riparia.
细纹蛙（Ranidella signifera）和溪边蛙（R. riparia）是细趾蟾科蛙类，分布范围基本异域，在南澳大利亚的弗林德斯山脉接触且分布范围有狭窄重叠。一种解释分布界限的假说是，每个物种无法在其分布范围之外的溪流中生存。在三条溪流的围场中测量了蝌蚪的存活和生长情况，一条在重叠区一侧，一条在另一侧，还有一条在重叠区内。当每个物种单独饲养时，无论是在细纹蛙溪流典型的缓水区，还是在溪边蛙溪流典型的急流区，它们之间都没有差异。当两个物种一起饲养时，在实验围场中水流被遮挡的任何溪流中，它们在存活或生长方面都没有一致的差异。在水流未被围场遮挡的地方，溪边蛙蝌蚪的存活率显著高于细纹蛙。提出了一种相互作用形式，即当溪边蛙存在时，细纹蛙更频繁地暴露在水流中。这可能解释了为什么细纹蛙没有将其分布范围扩展到溪边蛙占据的相邻快速岩石溪流中，但这些实验没有解释溪边蛙分布范围的限制。
