Intra-species recognition
Template:Short description Template:Redirect Template:Refimprove Intra-species recognition is the recognition by a member of an animal species of a conspecific (another member of the same species). In many species, such recognition is necessary for procreation.
Different species may employ different methods, but all of them are based on one or more senses.<ref name=":0">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The recognition may happen by the chemical signature (smell),<ref name=":1">Template:Cite journal</ref> by having a distinctive shape or color (sight),<ref name=":1" /><ref name=":2">Template:Cite journal</ref> by emitting certain sounds (hearing), or even by behaviour patterns. Often a combination of these is used.<ref name=":0" />
Among human beings, the sense of sight is usually in charge of recognizing other members of the same species, with maybe the subconscious help of smell. In particular, the human brain has a disproportionate amount of processing power dedicated to finely analyze the features of a human face. This is why most humans are able to distinguish human beings from one other (barring look-alikes), and a human being from a similar species like some anthropomorphic ape, with only a quick glance.
Some intra-species recognition is learned, for example in waterfowl, known as imprinting.<ref name=":0" /><ref name=":2" />
Intra-species recognition has been hypothesised as an explanation for the bizarre and varied structures found in dinosaurs, as it drives rapid evolution without a specific direction.<ref>Template:Cite journal</ref> However, this has raised criticism and the prevelance of species recognition in dinosaur evolution is doubted by many,<ref>Template:Cite journal</ref> not least because it's a vague concept.<ref>Template:Cite journal</ref>
Intra-species recognition systems are often subtle. For example, the chiffchaff and the willow warbler appear similar by eye, but their call distinguishes them greatly.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Sometimes, intra-species recognition is fallible: in many species of frog, males commonly misdirect their amplexus (mounting) to other species or even inanimate objects.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>Template:Cite journal</ref>
Heliconius charithonia displays intra-species recognition by roosting with conspecifics. They do this with the help of UV rhodopsins in the eye that help them distinguish between ultraviolet yellow pigments and regular yellow pigments.<ref>Bybee, Seth M., Furong Yuan, Monica D. Ramstetter, Jorge Llorente-Bousquets, Robert D. Reed, Daniel Osorio, and Adriana D. Briscoe. "UV Photoreceptors and UV- Yellow Wing Pigments in Heliconius Butterflies Allow a Color Signal to Serve Both Mimicry and Intraspecific Communication." The American Naturalist 179.1 (2012): 38–51. Web.</ref> They have also been known to emit chemical cues to recognize members of their own species.<ref>Sacledo, Christian (2010). "Environmental Elements Involved in Communal Roosting in Heliconius Butterflies (Lepidoptera:Nymphalidae)." Entomological Society of America 39 (3): 907–11</ref>