  Transients are fundamental to ecological systems with significant
implications to management, conservation, and biological control. We uncover a
type of transient synchronization behavior in spatial ecological networks whose
local dynamics are of the chaotic, predator-prey type. In the parameter regime
where there is phase synchronization among all the patches, complete
synchronization (i.e., synchronization in both phase and amplitude) can arise
in certain pairs of patches as determined by the network symmetry - henceforth
the phenomenon of "synchronization within synchronization." Distinct patterns
of complete synchronization coexist but, due to intrinsic instability or noise,
each pattern is a transient and there is random, intermittent switching among
the patterns in the course of time evolution. The probability distribution of
the transient time is found to follow an algebraic scaling law with a divergent
average transient lifetime. Based on symmetry considerations, we develop a
stability analysis to understand these phenomena. The general principle of
symmetry can also be exploited to explain previously discovered,
counterintuitive synchronization behaviors in ecological networks.
