First record of thanatosis in a Baja California Coachwhip, <i>Masticophis fuliginosus</i> (Cope 1895) (Squamata: Colubridae)

ior used by various prey species when threatened or in response to physical contact with a potential predator (Humphreys and Ruxton 2018).This behavior is generally used as a "last resort" (Fuentes et al. 2021) when other actions fail (Bauder et al. 2015).Snakes engaging in this behavior can assess their surroundings through chemical and visual cues, allowing them to evaluate escape opportunities (Durso and Mullin 2013; Zaartu and Urra 2020).Thanatosis has been documented across various ophidian taxa, including but not limited to Rena dulcis (Leptotyphlopidae) (Gehlbach 1970), Drymobius margaritiferus (Colubridae) (Farr and Lazcano 2011), Conophis vittatus (Dipsadidae) (Ahumada-Carrillo 2013), Micrurus tener (Elapidae) (Pineda 2013), Thamnophis elegans (Natricidae) (Gregory and Gregory 2006), Crotalus cerastes (Viperidae) (Thomas et al. 2020), and others (see Table 3 in Fuentes et al. 2021).Detailed studies of thanatosis often have focused on snakes in the genera Heterodon (Durso and Mullin 2013) and Natrix (Gregory 2008; Golubovic et al. 2021), using large samples and a pre-planned experimental design to statistically test the factors that influence this behavior.The Baja California Coachwhip (Masticophis fuliginosus) is a peninsular snake distributed from southern California, USA, to Los Cabos in Baja California Sur, Mexico, except for the region east of the San Pedro Mrtir Mountains and