Infanticide and Maternal Offspring Defence in European Rabbits under Natural Breeding Conditions

Abstract

Infanticide is an important source of mortality of dependent offspring in several mammal species, whereas female conspecifics are often the perpetrators. This has led to maternal counter‐strategies, such as the defence of the nests. However, cases of infanticide are hard to detect in the field, and studies on maternal offspring defence behaviour under natural breeding conditions are scarce. We conducted such a study on the European rabbit (Oryctolagus cuniculus), which is usually considered to show low maternal care. The study was carried out over 5 yr on a field enclosure population. We (1) studied infanticide rates and the impact of potential determinants: the group density and age structure of the females’ rank hierarchy within the groups; we used the latter as an estimator of social group stability. We (2) studied if mothers defend their breeding burrow against approaching, potentially infanticidal females. Overall, we recorded infanticide in 5% of all litters; infanticide was the cause in 12% of cases of litter mortality. The proportion of infanticide was 7% higher in groups where same‐age females occupied successive rank positions than in groups where the females’ rank hierarchy had a more heterogeneous and linear age structure. We hypothesize that social instability in the former groups was the reason for the increased infanticide risk. Infanticide rates were not correlated with group density and did not differ among mothers with different social ranks. Infanticide occurred exclusively during the first 10 d after parturition. During this time, mothers stayed closer to their breeding burrows than shortly before parturition or during later lactation. Moreover, mothers were more aggressive against other females in proximity to their breeding burrow than in more distant areas. We suggest that the pattern of spacing behaviour and intrasexual aggression of rabbit mothers are an adaptive response to the occurrence of female infanticidal behaviour.

Female home range size is regulated by resource distribution and intraspecific competition: a long-term field study

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Impact of rearing mangement on health in domestic rabbits: a review

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Effects of communal rearing and group size on breeding rabbits’ post-grouping behaviour and its relation to ano-genital distance

“…This means that they cannot fight and wound each other at the time of the reproductive cycle they are most likely to do so. Also, they cannot kill or wound each other's litters when these are still very young, immobile and vulnerable (a behaviour observed both in wild (Kunkele, 1992;Rodel et al, 2008) and commercial breeding rabbits (Szendro and Mcnitt, 2012)). However, postgrouping aggression and wounding are still common in these semi-group systems Rommers et al, 2014).…”