Bernd Heinrich And John Marzluff's Study
Summary: Bernd Heinrich and John Marzluff’s study on ravens and what their motives are for sharing demonstrated that Ravens do not share based on altruistic behavior. Rather, sharing among ravens is a result of dividing themselves into maturity groups, residents (territory holding adults) and wanderers (vagrant juveniles). Since juveniles do not often hold territory, they tend to sleep in roosts of about 15-50 ravens; these roosts are information centers that allow ravens to alert others about the location of a carcass. Juveniles that pursue a carcass together, called a gang, are less likely to be chased off from the food source by territory holding adults. Sharing in ravens benefit not just a single individual, but many individuals because