Fig. 2: Helpers invested more time helping at kin nests than at non-kin nests when both options were available.
From: A cryptic role for reciprocal helping in a cooperatively breeding bird
Points and error bars show mean and bootstrapped 95% confidence intervals for kinship bias in mean helping rates (that is, the difference in the proportion of time spent at nests of kin versus non-kin when both kinds of nest were present). a–d, Estimates of kinship bias for varying thresholds for defining kin (a kinship threshold of 0.1 means that relatedness above 0.1 is kin and relatedness below 0.1 is non-kin) for resident males (a), resident females (b), immigrant males (c) and immigrant females (d). The grey numbers above the x axes show the numbers of helpers of each type observed with opportunities to help both kin and non-kin on the same day. Means and confidence intervals were not calculated in cases with fewer than five helpers (which occurred only for immigrant females with thresholds of r > 0.4).
