An image of the animal should be provided. Where sexes look different, both should be shown. Where juveniles look different to the adults, or where several life cycle stages exist (e.g. larva, pupa, imago), each should be shown in a photograph. This requirement may be relaxed when the differences are not specific to the species and have already been illustrated in suitable photographs at a higher taxonomic level (e.g. tadpoles need not be included if their colouration is a bland black or brown, and when they have no other unique morphological adaptations that might be illustrated in a photograph, because the general tadpole morphology is already covered in text and pictures in the frog article).
All extant animals that make significant sounds should have these included in their article. This applies to all vocalisations, as well as other deliberate and characteristic sounds used in communication or predation. Excluded therefore are accidental sounds, which may include some made by feet, hooves, wings or flippers; chewing sounds and others produced as by-products of the dismemberment of prey, as well as accidental crushing of, say, vegetation. The emphasis is on whether the sound is made accidentally or with a clear function w.r.t. natural selection (including sexual selection).
More than one significant sound may have to be shown, and is permitted. Species that have highly variable local dialects or large individual differences should be represented by two or three clips roughly representative of the range of variation encountered in nature. Where subspecies differ, each recording should be correctly assigned to a subspecies.
The audio inclusion criteria do not apply to man (Homo sapiens sapiens), for whom separate criteria may have to be drawn up.
We could think about similar criteria for plants (distribution, seed morphology, flower morphology, leaf morphology, Gestalt).