Cold springs can affect the reproduction of rabbits as the rabbit's main priority is to survive before adding more to its family as they would already be struggling to keep itself warm. Yet alone a newborn rabbit which doesn't have any fur yet.
Also, cold springs could affect the amount of food that grows so the competition for food is more harsh so more rabbits are likely to die of starvation.
Though I'm not sure what your temperature range of a cold spring is so I might be giving extreme answers.
Explanation: Slaves were the main reason that there was food before the end when Abraham was president. Climate and slavery can change how the crops were grown. I'd also say the geography was messed up then due to the climate. (sorry if wrong Q-Q)
