... Different forms of sociality are thought to provide a variety of fitness benefits, including shared resources, reduced predation, improved communication or better access to mates (Eisenberg, Muckenhirn, & Rudran, 1972;Alexander, 1974;van Schaik, 1983;Emlen, 1984;Krause & Ruxton, 2002, Silk, 2007. Sociality may also come with costs associated with group living, including increased disease transmission (Ewald, 1994;Langwig, Frick, Bried, Hicks, Kunz, & Marm, 2012;Kappeler, Cremer, & Nunn, 2015), parasite load (Côt e & Poulinb, 1995;Whiteman & Parker, 2004), physiological stress (Creel, Dantzer, Goymann, & Rubenstein, 2013) and reproductive interference by other group members (Clutton-Brock et al., 1998;Lukas & Huchard, 2014), as well as the time and energy costs devoted to developing and maintaining social connections that could otherwise be devoted to activities directly related to individual survival or reproduction such as foraging or parental care. Given that these fitness benefits and costs of sociality may vary in direction or magnitude due to ecological circumstances such as food abundance, weather patterns or temporal variability in these factors (Emlen, 1994;Hatchwell & Komdeur, 2000;Rubenstein & Lovette, 2007;Schradin, K€ onig, & Pillay, 2010;Schradin & Pillay, 2005;Shen, Emlen, Koenig, & Rubenstein, 2017;Shuster & Wade, 2003), it is no surprise that there is considerable variation in the presence or expression of different types of social behaviours among species. ...