Recruitment in yellow-bellied marmot populations : kinship, philopatry and individual variability [Le recrutement dans les populations de marmottes à ventre jaune : parenté, philopatrie et variabilité individuelle].

Résumé

Recruitment of females forms matrilines, most of which become extinct and are repaced by immigrants. Mother/daughter or sister/sister kin groups share space. Philopatry characterizes matrilines but is not essential for their persistence. Matrilineal bifurcation is associated with the partitioning of a single space into two or more spaces, each of which is shared by individuals who are related by 0,5. Although the number of residents may not change, the total space used increases when matrilines bifurcate. Recruiters differ from nonrecruiters primarily in the number of female yearlings produced. Social females recruit a greater proportion of their yearling daughters than do asocial animals. Male turnover and the presence of unrelated adult females do not significantly affect recruitment, whereas an immigrant adult female nearly always prevents recruitment Recruitment of yearlings is more likely if they are philopatric, yearlings that wander widely disperse from their natal home ranges. lmmigration generally is associated with occupying an empty area. There is no evidence of sex ratio adjustment by successful recruiters.