SOCIAL-ORGANIZATION OF REINDEER (RANGIFER-TARANDUS), WITH SPECIAL REFERENCE TO RELATIONSHIPS AMONG FEMALES

In Finnish Lapland, level of association among nonrelated females in resting groups fluctuated with time. Among related females, only yearling daughters associated significantly with their respective mothers, although coexistence between mothers and yearling daughters was accompanied by antagonism. Two-year-old daughters were next in terms of association with their mothers, whereas daughters of ≥3 yr rarely associated with their mothers and the level of association decreased to the level observed for nonrelated females. When 2 herds joined each other, the frequency of antagonistic interactions among foreign individuals was initially quite high. Thereafter, the 2 herds became united as a new herd within 1-2 wek. A linear dominance hierarchy was found among 90 females that joined the studied herd. Social rank was correlated with body weight. Thereby, the dominance hierarchy was stably maintained even though the herd itself was a temporary association of individuals. During the nonrutting period, animals segregated by sex. Shedding of male antlers was correlated with drastic changes in ranking. -from Author