Individual recognition: it is good to be different. Trends Ecol Evol

Department of Ecology and Evolutionary Biology, University of Michigan, 830 N. University, Ann Arbor, MI 48109-1048, USA.
Trends in Ecology & Evolution (Impact Factor: 16.2). 11/2007; 22(10):529-37. DOI: 10.1016/j.tree.2007.09.001
Source: PubMed

ABSTRACT Individual recognition (IR) behavior has been widely studied, uncovering spectacular recognition abilities across a range of taxa and modalities. Most studies of IR focus on the recognizer (receiver). These studies typically explore whether a species is capable of IR, the cues that are used for recognition and the specializations that receivers use to facilitate recognition. However, relatively little research has explored the other half of the communication equation: the individual being recognized (signaler). Provided there is a benefit to being accurately identified, signalers are expected to actively broadcast their identity with distinctive cues. Considering the prevalence of IR, there are probably widespread benefits associated with distinctiveness. As a result, selection for traits that reveal individual identity might represent an important and underappreciated selective force contributing to the evolution and maintenance of genetic polymorphisms.

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Available from: J. Dale, Jan 07, 2015
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    • "In the pied babbler (Turdoides bicolor), we have considerable evidence for social recognition (Humphries 2014). This fits with the hypothesis that Sheehan and Bergman acknowledge that species living in small stable social groups should develop social recognition (Tibbetts and Dale 2007). We also have considerable evidence for quality signaling. "
    Behavioral Ecology 09/2015; DOI:10.1093/beheco/arv156 · 3.18 Impact Factor
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    • "The ability to discriminate individuals is a crucial skill whenever there are repeated interactions among various individuals differing in their intentions and requiring differential behavioural responses (Tibbetts and Dale 2007). "
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    ABSTRACT: Humans are part of the environment of domestic animals and interact with them daily, providing a good basis for the study of interspecific relationships. Abilities to discriminate and recognise individuals form the basis of these relationships, and they are crucial skills for domestic animals, since individual humans can differ in their behaviour towards them. At the same time, with experience, animals may develop a general memory of humans and generalise their behaviour towards strangers. This study aimed to determine the extent to which weaned piglets can discriminate familiar humans and generalise their past experience when faced with unfamiliar humans. Forty-eight groups of three piglets were submitted to two consecutive 5-day conditioning periods of the same or opposite valence (positive and/or negative) given by one (A) or two (A then B) handlers. The reactivity of piglets to a motionless human and to an approaching human was measured before and after conditioning periods with unfamiliar and familiar handlers. Thereafter, piglets which received treatments with the two handlers A and B were subjected to a choice test between both handlers. The reactivity to an approaching human appeared to better reflect the past experience with familiar handlers since piglets clearly recognised them and adapted their behaviour accordingly. In contrast, reaction of piglets to a motionless human reflected their natural propensity to seek interaction, even after a negative experience. Although piglets were able to extend their memory of humans to an unfamiliar human through generalisation, many factors seemed to interact in this process, especially the complexity of the previous experience (inconsistent vs consistent) and the context in which piglets met the unfamiliar human (motionless vs approaching). We conclude that discrimination and generalisation processes of reactivity to humans do not simply rely on past interactions, but also depend on the context according to the degree of similitude with their past experience.
    Animal Cognition 07/2015; DOI:10.1007/s10071-015-0900-2 · 2.58 Impact Factor
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    • "In all social-living animals, including humans, recognition of other individuals is one of the most important social-cognitive abilities (e.g., Tibbetts and Dale 2007). "
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    ABSTRACT: Bottlenose dolphins are known to use signature whistles to identify conspecifics auditorily. However, the way in which they recognize individuals visually is less well known. We investigated their visual recognition of familiar human individuals under the spontaneous discrimination task. In each trial, the main trainer appeared from behind a panel. In test trials, two persons (one was the main trainer) appeared from the left and right sides of the panel and moved along the poolside in opposite directions. Three of the four dolphins spontaneously followed their main trainers significantly above the level of chance. Subsequent tests, however, revealed that when the two persons wore identical clothing, the following response deteriorated. This suggests that dolphins can spontaneously discriminate human individuals using visual cues, but they do not utilize facial cues, but body area for this discrimination.
    SpringerPlus 07/2015; 4(1):352. DOI:10.1186/s40064-015-1147-8
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