The first one, as a teaser:

Red fox. Photo: Charles G. Summers, Jr.

Long before the male red fox's love gets tough, he is an attentive, indulgent mate and father. For the first month after the birth of his young, his vixen must stay in her den, doubling as a food source and thermal blanket for their young. Dad's job is providing her with food every four to six hours until she can leave the den and start hunting as well. Researchers have seen fox dads exhibiting much excitement about their pups, playing with them endlessly. One father was even observed waiting for a watchful aunt to fall asleep and then quietly calling to his pups to come play with him. After three months, it's time for life's first harsh lesson: no more free meals. "Through years of observation, I've come to believe parents start reducing food as a tactic to get the pups moving away from the den," says David Henry, ecologist for the Canadian National Parks. "And it's the father that takes the lead with this strategy." Fox fathers don't just leave their young hungry, however, they help teach survival skills. They bury surplus food close to the den and disguise it with leaves and twigs. This technique, says Henry, teaches the pups to sniff and forage. Biologist Shelly Pruss (one of Henry's students) studied the closely related swift fox in a region where they were being killed by coyotes. There, she saw a male fox playing ambush with his offspring as if teaching them how to escape from predators.