intra-species recognition

{{Short description|Recognition of another member of the same species}}

{{redirect|Species recognition|automated species recognition|Automated species identification}}

{{Refimprove|date=September 2014}}

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{{Cite web |date=2010-11-18 |title=How do animals recognise other members of their own species? |url=https://www.sciencefocus.com/nature/how-do-animals-recognise-other-members-of-their-own-species |access-date=2025-05-13 |website=BBC Science Focus Magazine |language=en}}. The recognition may happen by the chemical signature (smell){{Cite journal |last=Secondi |first=J. |last2=Johanet |first2=A. |last3=Pays |first3=O. |last4=Cazimajou |first4=F. |last5=Djalout |first5=Z. |last6=Lemaire |first6=C. |date=2010 |title=Olfactory and visual species recognition in newts and their role in hybridization |url=https://www.jstor.org/stable/25799781 |journal=Behaviour |volume=147 |issue=13/14 |pages=1693–1712 |issn=0005-7959}}, by having a distinctive shape or color (sight){{Cite journal |last=Hailman |first=Jack P. |date=1959 |title=Why is the Male Wood Duck Strikingly Colorful? |url=https://www.jstor.org/stable/2458458 |journal=The American Naturalist |volume=93 |issue=873 |pages=383–384 |issn=0003-0147}}, by emitting certain sounds (hearing), or even by behaviour patterns. Often a combination of these is used.

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.

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.{{Cite journal |last=Padian |first=K. |last2=Horner |first2=J. R. |date=2011 |title=The evolution of ‘bizarre structures’ in dinosaurs: biomechanics, sexual selection, social selection or species recognition? |url=https://zslpublications.onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.2010.00719.x |journal=Journal of Zoology |language=en |volume=283 |issue=1 |pages=3–17 |doi=10.1111/j.1469-7998.2010.00719.x |issn=1469-7998}} However, this has raised criticism and the prevelance of species recognition in dinosaur evolution is doubted by many{{Cite journal |last=Hone |first=D. W. E. |last2=Naish |first2=D. |date=2013 |title=The ‘species recognition hypothesis’ does not explain the presence and evolution of exaggerated structures in non-avialan dinosaurs |url=https://zslpublications.onlinelibrary.wiley.com/doi/10.1111/jzo.12035 |journal=Journal of Zoology |language=en |volume=290 |issue=3 |pages=172–180 |doi=10.1111/jzo.12035 |issn=1469-7998}}, not least because it's a vague concept{{Cite journal |last=Mendelson |first=Tamra C. |last2=Shaw |first2=Kerry L. |date=2012-08-01 |title=The (mis)concept of species recognition |url=https://linkinghub.elsevier.com/retrieve/pii/S0169534712000882 |journal=Trends in Ecology & Evolution |language=English |volume=27 |issue=8 |pages=421–427 |doi=10.1016/j.tree.2012.04.001 |issn=0169-5347 |pmid=22575840}}.

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.{{Cite web |last=Trust |first=Woodland |date=2025-03-02 |title=Chiffchaff or Willow Warbler? |url=https://www.woodlandtrust.org.uk/blog/2025/02/chiffchaff-or-willow-warbler/ |access-date=2025-05-13 |website=Woodland Trust |language=en-GB}} Sometimes, intra-species recognition is fallible: in many species of frog, males commonly misdirect their amplexus (mounting) to other species or even inanimate objects.{{Cite web |title=Why Do Frogs Keep Trying to Mate with the Wrong Things? |url=https://www.discovermagazine.com/planet-earth/why-do-frogs-keep-trying-to-mate-with-the-wrong-things |access-date=2025-05-13 |website=Discover Magazine |language=en}}{{Cite journal |last=Soni |first=Shubham P |last2=Apte |first2=Vaishnavi |last3=Joshi |first3=Pranav |last4=Cyriac |first4=Vivek P |date=2024-07-03 |title=Barking up the wrong frog: global prevalence of misdirected amplexus in anuran amphibians |url=https://academic.oup.com/biolinnean/advance-article-abstract/doi/10.1093/biolinnean/blae062/7705636?redirectedFrom=fulltext |journal=Biological Journal of the Linnean Society |pages=blae062 |doi=10.1093/biolinnean/blae062 |issn=0024-4066}}

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.Bybee, Seth M., Furong Yuan, Monica D. Ramstetter, Jorge Llorente-Bousquets, Robert D. Reed, Daniel Osorio, and Adriana D. Briscoe. "[https://www.researchgate.net/profile/Adriana_Briscoe/publication/51883446_UV_Photoreceptors_and_UV-Yellow_Wing_Pigments_in_Heliconius_Butterflies_Allow_a_Color_Signal_to_Serve_both_Mimicry_and_Intraspecific_Communication/links/0912f503cdc1cbc119000000.pdf 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. They have also been known to emit chemical cues to recognize members of their own species.Sacledo, Christian (2010). "[https://www.researchgate.net/profile/Christian_Salcedo/publication/44675826_Environmental_Elements_Involved_in_Communal_Roosting_in_Heliconius_Butterflies_Lepidoptera_Nymphalidae/links/58c95ec6a6fdcc63aa98d0af/Environmental-Elements-Involved-in-Communal-Roosting-in-Heliconius-Butterflies-Lepidoptera-Nymphalidae.pdf Environmental Elements Involved in Communal Roosting in Heliconius Butterflies (Lepidoptera:Nymphalidae)]." Entomological Society of America 39 (3): 907–11