Definition: A taxon is Vulnerable when the best available evidence indicates that it meets any of the criteria A to E for Vulnerable, and it is therefore considered to be facing a high risk of extinction in the wild.
Definition: the air-filled cavity within the skull of vertebrates that lies between the outer ear and the inner ear. It is linked to the pharynx (and therefore to outside air) via the Eustachian tube and in mammals contains the three ear ossicles, which transmit auditory vibrations from the outer ear (via the tympanum) to the inner ear
Definition: Basal metabolic rate (BMR) is the amount of energy expended daily by humans and other animals at rest. Rest is defined as existing in a neutrally temperate environment while in the post-absorptive state.
Definition: 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.
Definition: Because of the difference in refractive index between air and water (or corneal tissue), a curved cornea is an image-forming lens in its own right. Its focal length is determined by the radius of curvature of the cornea. Many corneal eyes (eg: in land vertebrates) also have lenses, but the lens is flattened and weakened compared with an aquatic lens; most of the refractive power is provided by the cornea. Corneal eyes cannot focus in aquatic habitat.