Contribution of within-litter interactions to individual differences in early postnatal growth in the domestic rabbit

Individual differences in early body mass affect thermogenic performance and sibling interactions in litter huddles of the house mouse

“…However, huddling together with siblings is a dynamic process characterized by frequent changes in the pups' positions relative to littermates, reflecting their competition for thermally advantageous positions in the center of the huddle (Alberts, 1978;Bautista et al, 2008). Bautista, Zepeda, et al, 2015). Furthermore, relatively lighter pups generally spent less time in contact with their siblings, presumably due to their higher probability of being forced to occupy peripheral positions and even to temporarily loose contact with the huddle (cf.…”

“…These were used to test for changes across time in peripheral body temperature in response to thermal challenge, and for correlations of sibling differences in body mass with individual slopes describing the bodytemperature dynamics in response to a thermal challenge and with the pups' interactions within the huddle. Sibling differences in body mass were calculated as the deviation from the litter mean (Bautista, Zepeda, et al, 2015;Rödel, Bautista, Roder, Gilbert, & Hudson, 2017). We always included litter identity (n = 12 litters) and parental identity (n = 8 pairs) as random factors (random intercepts) in the analysis to take into account these two sources of same origin of F I G U R E 1 Changes in maximum peripheral body temperature in response to a thermal challenge.…”

“…Furthermore, relatively lighter pups generally spent less time in contact with their siblings, presumably due to their higher probability of being forced to occupy peripheral positions and even to temporarily loose contact with the huddle (cf. Bautista, Zepeda, et al, 2015).…”

“…Huddling together with litter siblings during early postnatal life is a highly efficient strategy of communal thermoregulation in altricial and polytocous species, helping to conserve energy essential for early growth and survival, and particularly in the absence of the mother or other care givers (Blumberg & Sokoloff, 1998;Gilbert et al, 2010). Studies in the domestic rabbit and in the laboratory rat Rattus norvegicus have shown that pups with relatively lower birth mass typically occupy more peripheral positions in the huddle than their heavier siblings, despite showing comparatively more attempts to reach a thermally more advantageous position in the center Bautista, García-Torres, Prager, Hudson, & Rödel, 2010;Bautista, Zepeda, et al, 2015;Rödel, Bautista, et al, 2008). Studies in the domestic rabbit and in the laboratory rat Rattus norvegicus have shown that pups with relatively lower birth mass typically occupy more peripheral positions in the huddle than their heavier siblings, despite showing comparatively more attempts to reach a thermally more advantageous position in the center Bautista, García-Torres, Prager, Hudson, & Rödel, 2010;Bautista, Zepeda, et al, 2015;Rödel, Bautista, et al, 2008).…”

“…This has been intensively studied in different species of altricial mammals and birds (Alberts, 1978;Blumberg & Sokoloff, 1998;Forbes, 2005;Gilbert, McCafferty, Giroud, Ancel, & Blanc, 2012;Hill, 1983;Rödel, Hudson, & von Holst, 2008;Sokoloff & Blumberg, 2001), including the laboratory mouse (Mus musculus: Harshaw & Alberts, 2012;Harshaw, Culligan, & Alberts, 2014;Shelton & Alberts, 2018). Studies in the domestic rabbit and in the laboratory rat Rattus norvegicus have shown that pups with relatively lower birth mass typically occupy more peripheral positions in the huddle than their heavier siblings, despite showing comparatively more attempts to reach a thermally more advantageous position in the center Bautista, García-Torres, Prager, Hudson, & Rödel, 2010;Bautista, Zepeda, et al, 2015;Rödel, Bautista, et al, 2008).…”