Newborn spotted hyaenas are born entirely black and one will often kill the other in order to receive more food and mature faster.
Newborn spotted hyaenas weigh from 1 to 1.6 kilograms and are quite precocious, being born with their eyes open. Newborns are almost entirely black.
If siblings are the same sex, they begin fighting violently soon after birth, which usually results in the death of one of the two. Since single young receive more food and mature faster, this behavior is probably adaptive.