“…Many species cease all feeding at the onset of initiation (including one fish; Penttinen & Holopainen, 1992), and animals often dramatically decrease their digestive system volume (Cramp et al., 2009; Hahn & Denlinger, 2011; Hume et al., 2002; Martin et al., 2008; Naya et al., 2009). The gut microbiome of many animals is also modified as animals begin fasting during initiation (Bailey et al., 2010; Carey et al., 2013; Gossling et al., 1982; Liu et al., 2016; Secor & Carey, 2016; Sommer et al., 2016). For animals that consume food intermittently during dormancy, such as food‐caching rodents, some bats, bears and some insect larvae (Avery, 1985; Boyles et al., 2006; Goddeeris et al., 2001; Humphries et al., 2003; Kirby et al., 2019; Krofel et al., 2016; López et al., 1995; Pigeon et al., 2016; Turbill, 2008), digestive system volume may still be reduced, but maintaining a more active gut throughout winter is likely to increase overall maintenance costs (Humphries et al., 2003).…”