Now imagine how much more work they have when suddenly they have another whole batch of mouths to feed. A pair of loons have to find food for themselves and help their two chicks learn to catch fish. A pair of chickadees must find insects for themselves and their six or even eight helpless nestlings. Foxes, squirrels, and manatees must eat enough to support their own body with calories to spare for producing their milk to feed their babies. It isn't just a coincidence that so many baby animals are born or hatched right when there is an abundance of food.
Critters time their reproductive cycle to maximize the chances of their babies' survival.
Baby owls and hawks hatch out when receding snows are exposing mice just the right size for their little mouths, and by the time they're learning to hunt on their own a few weeks after hatching, there are lots of inexperienced other baby animals around to practice on. Hummingbirds hatch when there is an abundance of flowers to provide nectar and tiny insects. Goldfinches wait until their favorite plants, like thistle and milkweed, are producing lots of seeds. They use the downy seeds for building their nests as well as eating. Wolves pups are born in the arctic when caribou are calving, so their mother will be able to produce milk and so the babies will have easy hunting as they learn.