Final answer:
The population cycles of collard lemmings are influenced by a combination of predation from predators like the lynx and density-dependent factors like crowding, which affects reproduction rates in hares.
Step-by-step explanation:
The population cycles of collard lemmings are driven by complex interactions that include both predation and density-dependent factors. Prey population cycles, such as those of the hares, are affected by lower fecundity (maternal stress) caused by crowding, which in turn can affect predator populations, like the lynxes, due to their reliance on hares for food. The interactions between these factors highlight the sophisticated dynamics occurring in ecosystem population models.
When predation pressure from lynxes is low, the hare population size begins to increase, which then initiates a new cycle. These cycles are reflective of intricate predator-prey dynamics, where prey populations may increase and decrease cyclically in response to their predator populations' mirror-image fluctuation in size. However, researchers also consider undefined density-dependent factors as significant in influencing these population cycles.