Nature Being Irrational.

My bird tables attracts both birds and squirrels, and I often see male birds and squirrels chasing females away from the food during winter. But when the breeding period arrives I sometimes see males feeding females while they’re sitting eggs or caring for new-borns. This would suggest that nature only values females during the breeding period.

This seems irrational to me. A male bird or animal can breed with any number of females, whereas the ladies’ capacity to breed is limited by the gestation period. Surely it would make more sense for nature to favour the females all year round, since it’s more important to preserve their numbers. Am I missing something?