Additionally, matrilines having higher average coefficient of relatedness initiate significantly fewer fights using intense aggression than matrilines having lower average coefficient of relatedness (β = −0.15, P = 0.008; Figure 4).
Groups with a higher group-mean average coefficient of relatedness per matriline showed lower rates of wounding (β = −4.11, P = 0.04; R2 = 0.52).
Groups with a lower group-mean matrilineal coefficient of relatedness had higher rates of wounding and more communities per matrilineal groom network, suggesting that there is a cumulative effect of matriline-level instability on group-level instability.
This analysis revealed the same relationship between matriline fragmentation and community structure on the group-level as was found for the matriline-level: groups having a higher average value of the average coefficient of relatedness per matriline have a lower average value of communities per matriline (β = −22.4, P = 0.046; R2 = 0.69).
Matrilines with a lower average coefficient of relatedness participated in a higher proportion of fighting-events in which both combatants were members of that matriline (β = −0.43, P<0.0001).
As predicted, matrilines with a lower average coefficient of relatedness participated in a higher proportion of fighting-events involving intense aggression in which both combatants were members of that matriline and directed intense aggression at one another (β = −0.48, P<0.0001; Figure 5).
The two members of a family-related pair were more frequently found within the same cluster than in different clusters; the coefficient of relatedness was also significantly higher within clusters compared to whole population relatedness (r 2 = 0.046).
Specifically, we tested whether squirrels discriminate between the rattles of neighbours and non-neighbours, and kin (coefficient of relatedness, r ≥ 0.25) and non-kin (r < 0.125).
The variables matriline size and average coefficient of relatedness per matriline are negatively correlated (r = −0.58).
Among our study groups, those that have been together longer had lower values of group-mean matrilineal coefficient of relatedness.
