Factor of familiarity in sibling recognition in golden hamsters

Male hamsters, reared with their siblings and non-siblings, were tested for their exploratory behavior of conspecific in the 4th and 8th week after their birth. During the tests, a familiar sibling, an unfamiliar sibling, a familiar non-sibling and an unfamiliar non-siblings was presented in a choice box. Subjective distance among these testing animals was measured using the caseV of Thurston's paired-comparison test. The hamsters spent more time with the unfamiliar animals than with the familiar ones. Although biological relation (sibling or non-sibling) had a significant effect in the 4th-week test, only the familiarity determined the investigatory behavior in the 8th-week test. These results suggest sibling recognition based on learning in hamsters.