定義： The duration of the development from fertilized, deposited or implanted egg to hatching/birth. Corresponds to egg incubation duration in oviparous animals and to gestation period duration in viviparous animals.
定義： Number of individuals in a group that spends the majority of their time in a 24 hour cycle together where there is some indication that these individuals form a social cohesive unit.
定義： Age when primary nutritional dependency on the mother ends and independent foraging begins to make a major contribution to the offspring’s energy requirements.
