التعريف: 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.
التعريف: 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.
التعريف: A group of species that exploit the same food resources, and/or use the same feeding or foraging methods. http://en.wikipedia.org/wiki/Guild_(ecology)
