Effects of siblings on reproductive maturation and infanticidal behavior in cooperatively breeding Mongolian gerbils

Abstract

Mongolian gerbils living with their natal families undergo delayed reproductive maturation while helping to rear their younger siblings, whereas those housed away from their natal families may mature earlier but often respond aggressively to unfamiliar pups. We tested whether cohabitation with pups contributes to reproductive suppression and inhibition of infanticidal behavior, using young males and females housed with (1) their parents and younger siblings (pups), (2) parents without pups, (3) mixed-sex littermate groups, or (4) mixed-sex groups of unrelated peers. Maturation in males was inhibited by cohabitation with the parents, while maturation in females was further suppressed in the presence of pups. Males in all housing conditions showed little aggression towards unfamiliar pups, whereas females were usually infanticidal unless housed with pups. Aggression toward pups was especially pronounced in females that were pregnant or undergoing ovulatory cycles. Thus, cohabitation with younger siblings may intensify reproductive suppression and inhibit infanticidal behavior in female gerbils, whereas male gerbils exhibit parentally-induced reproductive suppression and low rates of infanticide even in the absence of younger siblings.

Social competition and its consequences in female mammals

“…Mothers whose pups are killed typically occupy nursery burrows close to the killers and are smaller and lighter than their neighbours and, in many cases, are close relatives of the females that attack them. Similarly, in meerkats and marmosets, dominant females that are pregnant commonly kill the newborn offspring of subordinate females that give birth in the group, which would otherwise be heavier than their own future offspring (Clutton‐Brock et al ., 1998 b ; Young & Clutton‐Brock, ; Saltzman et al ., ). In meerkats, subordinate females are commonly the daughters of dominants, so that dominant females frequently kill their own grand‐offspring (Clutton‐Brock et al ., 1998 b ; Young et al ., ).…”

Paternal Care in Biparental Rodents: Intra- and Inter-individual Variation

“…This effect is age-limited, however: nurturant behavior toward experimentally presented pups decreases from the young juvenile period to adulthood, and previous cohabitation with younger siblings does not affect pup-directed behavior in older juveniles or adults (Gubernick and Laskin 1994). In Mongolian gerbils, unlike both prairie voles and California mice, cohabitation with younger siblings does not appear to alter behavioral responses to pups in adult virgin males, in terms of frequency of infanticide (Elwood 1980;Saltzman et al 2009); however, effects on parental behavior per se have not been evaluated.…”

Alloparenting enhances the emotional, social and cognitive performance of female African striped mice, Rhabdomys pumilio

“…development of parental care skills; Salo & French, 1989) and less attention has been paid to the ontogeny of alloparental behaviour (e.g. interactions with siblings has long-term effects on individual responsiveness to young; Saltzman et al, 2009).…”