Elephant

Females prefer bigger, stronger, and, most importantly, older males. Such a reproductive strategy tends to increase their offspring's chances of survival.
After a twenty-two-month pregnancy, the mother gives birth to a calf that weighs about 115 kg (250 lb) and stands over 75 cm (2.5 ft) tall. Elephants have a very long development. As is common with more intelligent species, they are born with fewer survival instincts than many other animals. Instead, they rely on their elders to teach them what they need to know. Today, however, the pressures humans have put on the wild elephant populations, from poaching to habitat destruction, mean that the elderly often die at a younger age, leaving fewer teachers for the young. The consequences of this for the next generation are not known.
A new calf is usually the center of attention for herd members. Adults and most of the other young will gather around the newborn, touching and caressing it with their trunks. The baby is born nearly blind and at first relies almost completely on its trunk to discover the world around it.
Elephants within a herd are usually related, and all members of the tightly-knit female group participate in the care and protection of the young. After the initial excitement, the mother will usually select several full-time baby-sitters, or "allomothers", from her group. An elephant is considered an allomother when she is not able to have her own calf. The more allomothers, the better the calf's chances of survival. A benefit of being an allomother is she can gain experience or receive assistance when caring for her own calf. According to Cynthia Moss, a well known researcher, these allomothers will help in all aspects of raising the calf. They walk with the young as the herd travels, helping the calves along if they fall or get stuck in the mud. The more allomothers a calf has, the more free time its mother has to feed herself. Providing a calf with nutritious milk means the mother has to eat more nutritious food herself.