Animals that actively defend territories. The area being defended is the territory. An example is a dog.$^1$
Living in a group helps animals defend themselves against predators in several ways. Lone animals must rely only on their own senses, but an animal in a group benefits by having lots of other animals senses to keep them alert of danger. An example is a wolf pack.$^1$
A form of dyadic relationship in which an individual has only one partner during their lifetime.$^1$
It is a behavioral and evolutionary strategy adopted by some animals. It involves a parental investment being made to the evolutionary fitness of offspring. Patterns of parental one are widespread and highly diverse across the animal kingdom.$^1$
It is the act of deliberately killing infants.$^1$