Global distribution of cooperatively breeding and of socially monogamous mammals:

Global distribution of (a) cooperatively breeding and of (b) socially monogamous mammals. Cooperatively breeding mammals are rare, and not more than seven species can be found simultaneously in one area (a). Cooperative breeders tend to occur in areas that are more marginal, in contrast to most socially monogamous species in which parents receive no alloparental care which live around the equator (b).

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