P3.23 Sunday, Jan. 6 Ontogenesis of Group Regulatory Behavior in Mouse Litters SHELTON, DS*; ALBERTS, JR; Indiana University-Bloomington; Indiana University-Bloomington firstname.lastname@example.org
Individual developmental trajectories are shaped by social stimuli (e.g., parental care, dominance relations), and environmental cues (e.g., light, temperature, food). In theory, both kinds of cues should also affect group behavior that emerges from individual interactions, but such relations have not been studied systematically. In the microenvironment of the natal nest, litters of mouse pups behave adaptively as a group. We tested the effects of environmental variables on the group behavioral regulation in developing mice (Mus musculus, C57BL/6). Huddle surface areas of Postnatal Day (PND) 2, 4, and 8 mice were monitored on flat and concave substrates at 22°C and 36°C. Group behavioral regulation was seen at all ages, with the litters forming compact huddles at cool temperatures and more dispersed aggregations at warm temperatures. On the concave, but not on the flat surface ‘pup flow’ was manifested, as individuals appeared and disappeared throughout the group. Pup flow rate was temperature-dependent. Huddles of six pups made an average of 215 flow movements/hr at 22°C; flow rate decreased by >40% at lower and higher temperatures. There was also a developmental emergence of temperature-modulated direction in pup flow. These findings provide insight into how physical and behavioral parameters of a nest environment shape individual behaviors from which adaptive group behavior emerges.