Siberian jay friendship test : A study on group cohesion

摘要: Group and family living is an integral part of many animals’ ecology. Thus the behavior became associated with plenty advantages as well disadvantages. However, rarely has actual concept group been investigated. Questions such as, “What constitutes a ‘group’?” “Do individuals within these ‘groups’ associate each other frequently enough to actually enjoy benefits living?” are seldom asked. With questions in mind, aim this study was use Siberian jay (Perisoreus infaustus) their territories explore shed more light on issue extent living. A working definition ‘group’ made subsequently birds were observed natural habitat northern Sweden during several seasons. Consequently, pair-wise coherence index (CI) created quantify levels association between territory order investigate which possible factors affect cohesion. Results indicate that cohesion strongly dependent kinship birds. Moreover, it found alpha kin had significantly higher values than non Thus, territory, formed core being much less individuals. This contrast hypothesis, predicted form solely, having lower coherence. Interestingly, no effect type season territorial group. further evidence sub-grouping even level, thus suggesting yet complex interplay members. All all, low values, casts fact if present they might not necessarily be tight unit unable fully benefit from