Of beavers and salamanders
Complex life cycle species such as amphibians depend on seasonal wetlands for reproduction. However, breeding habitat quality varies over time and space. Gill (1978) proposed that beaver ponds are composed of "hotspots" for reproduction of newts that create a mosaic of sources and sinks. We sampled a large landscape composed of ~200 breeding ponds to test whether other species of salamanders show a similar pattern of "hotspots".
We found a similar pattern of hotspots where reproductive success of ringed salamanders varied greatly across breeding ponds with very few ponds potentially contributing to landscape processes. Similar patterns in different regions and species suggests that source-sink dynamics may be a general mechanism for maintaining salamander metapopulations.