Females are larger than males in more species of mammals than is generally supposed. A provisional list of the mammalian cases is provided. The phenomenon is not correlated with an unusually large degree of male parental investment, polyandry, greater aggressiveness in females than in males, greater development of weapons in females, female dominance, or matriarchy. The phenomenon may have evolved in a variety of ways, but it is rarely, if ever, the result of sexual selection acting upon the female sex. The most common selective pressures favoring large size in female mammals are probably those associated with the fact that a big mother is often a better mother and those resulting from more intense competintion among females for some resource than among males. It appears that, in general, more than one such pressure must affect the females of a species, and that their combined effects must not be countered by even stronger selective pressures favoring large size in males, before the result is that of larger size in the female sex. Sexual selection may often be operating upon the male sux in mammals even when it is smaller. Present knowledge about the species of mammals in which females are lager than males is quite rudimentary. Much more information is needed before we will be able to speak of the selective pressures accounting for the phenomenon with any reasomable degree of certainty. Perhaps the most fruitful approach would be a series of field studies of groups of related species in which females are larger in some species and males are larger in others.

Mammals in which females are larger than males.

In order to obtain a better knowledge of the behaviour of the domestic pig, a small population was established in 1978 near Edinburgh in an enclosure with several types of habitat, including woodland and bog. Over a 3·5-year period 13 different groups were studied with each group typically containing a boar, four sows, a young sub-adult boar and an immature gilt. The sow and her piglets were allowed to determine the time of weaning and, apart from providing food for maintenance and reproduction, handling was kept to a minimum. The behaviour of these pigs, which included most of the behaviour of the European wild boar, is described in a general manner for the non-specialist.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0003356100040411

The behaviour of pigs in a semi-natural environment

The use of pigs in neuroscience: modeling brain disorders.

In a discussion of the evolution of gene flow, Wilson (1975, p. 103) pointed out that a tendency for different sexes and age groups to migrate differentially can exert a profound influence on social structure. In this paper, I suggest that the reverse is equally true: a basic social structure—namely, the dominance hierarchy—can strongly influence the differential dispersal and migration of different sexes and age groups and thereby serve an important function in population dynamics.

The Ecological Significance of Behavioral Dominance

An early view of the development of adaptive and maladaptive behaviors during childhood
and adolescence suggested that such outcomes stemmed largely from the quality of the child’s
relationship with his or her parents and from the types of socialization practices that the
parents engaged in. This primary focus on the developmental signiﬁcance of the parent-child
relationship and of parenting practices was proposed early by Freud (1933) in his theory of
psychosexual development, by Sears, Maccoby, and Levin (1957) in their seminal research on
the signiﬁcance of discipline variability and social learning, and by Bowlby (1958) in his
inﬂuential writings on the long-term developmental importance of the mother-infant
attachment relationship. Without denying the veracity of these claims, it is nevertheless the
case that adjustment and maladjustment in childhood stem from a wide variety of sources
including genetic and biological underpinnings and social inﬂuences other than parents. For
example, children and adolescents spend enormous amounts of time, both in and out of
home, relating to and interacting with many other people of potential inﬂuence. These signiﬁcant others include their siblings, teachers or out-of-home caregivers, and peers. Children’s
peers are the focus of the present chapter.

G.B. Meese

Papers

The establishment and nature of the dominance hierarchy in the domesticated pig

Individual recognition and the dominance hierarchy in the domesticated pig. The role of sight

The use of Large Animal Immobilon in pigs