Absence of kin discrimination in the hatchlings of a lizard, Calotes versicolor (Agamidae)

Abstract

Laboratory born Calotes versicolor hatchhngs were reared for 15 days in pure or mixed sibships or singly in isolation and then tested for their kin discrimination abihty. As C. versicolor orients itself visually, visual displays like push-ups, guiar extensions, and distance between the test individuals were used as indicators of arousal/aggression towards the opponents (famihar vs. famihar/unfamiliar sib or non-sib). The hatchhngs exhibited aggressiveness towards unfamihar sibs as well as non-sibs in the form of push-ups and guiar extensions; they also remained at a longer distance from each other. In contrast, they did not exhibit such behaviors against famihar individuals regardless of their relatedness, and stayed closer to each other. In tests involving once famihar individuals, sib, or non-sib reared together for 15 d from hatching and then separated for 7 or 30 d, the lizards showed aggressiveness towards each other following 30 d separation. A greater number of push-ups and guiar extensions were exhibited by the test individuals after 30 d separation compared to those separated for 7 d. Thus, in this non-social lizard, there is no kin discrimination. An early dispersal of hatchhngs in this species may have led to a loss of kin discrimination. However, familiar individuals are recognized as long as they continue to remain famihar thereby suggesting a 'dear enemy phenomenon'.

Spring 2021

“…Refuge sharing is particularly interesting as C. versicolor is popularly known to show agonistic behaviour towards conspecifics; adult male-male fights are common, and female-female aggression has also been observed in juveniles (Pandav et al, 2007;Ammanna et al, 2013;Ammanna, 2015;Barnes & Tipprapatkul, 2019). However, a "dear enemy" phenomenon was suggested by Ammanna et al (2013) based on their intraspecific interaction studies on captive specimens.…”

“…Refuge sharing is particularly interesting as C. versicolor is popularly known to show agonistic behaviour towards conspecifics; adult male-male fights are common, and female-female aggression has also been observed in juveniles (Pandav et al, 2007;Ammanna et al, 2013;Ammanna, 2015;Barnes & Tipprapatkul, 2019). However, a "dear enemy" phenomenon was suggested by Ammanna et al (2013) based on their intraspecific interaction studies on captive specimens. They reveal the presence of differential aggression towards familiar and non-familiar conspecifics, where the specimens showed reduced aggression towards familiar individuals and the familiarity dissipated after 30 days of physical separation.…”