Abdominal odours of young, low-ranking European rabbit mothers are less attractive to pups: an experiment with animals living under natural breeding conditions

Abstract

Lactating rabbit females (Oryctolagus cuniculus) emit abdominal, ventral odour cues that are involved in guiding the pups to the nipples. We tested the impact of the females' social rank and age on the emission of this odour signal; both factors are highly collinear in wild rabbits and we did not aim to disentangle them in our study. We predicted that the abdominal odours of young, low-ranking females, which are usually more stressed and have a comparatively lower body condition, should be less attractive to pups than those of older, high-ranking females. For the experiment, we caught females from a population of wild-type European rabbits living in a large field enclosure. Pairs of adult females were placed in boxes with wire-mesh floor fixed over an arena with three rabbit pups aged 4-7 days old. First, we evaluated the effectiveness of our two-choice design by testing lactating females (LF) against non-lactating (NLF) controls (n = 17 pairs). In accordance with recent studies, the pups showed a clear preference for lactating females by means of a higher exploration time and more local searching under the ventral region of these females. In a second experiment, the pups chose between lactating 1-year-old, low-ranking females (Y/LRF) and older, high-ranking females (O/HRF) (n = 10 pairs). These latter assays suggested a comparatively lower attractiveness of Y/LRF females to pups searching for milk. Although the pups showed no significant preference in exploration behaviour, they preferably directed local searching events to the abdominal region of O/HRF females. In conclusion, our study suggests that motheroffspring chemosensory communication is modified by the mother's age and social rank, i.e., by a complex of factors that are strongly linked in rabbit females in the wild.

Early development influences ontogeny of personality types in young laboratory rats

“…The bottom of the test arena consisted of a flat, closed glass tank which had a constant temperature of 308C due to a continuous flow of warm water (cf. Rödel, Coureaud, Monclús, Föhn, & Schaal, 2009). This was done in order to prevent cooling and inactivity in the 11-day-old pups.…”