Conophis lineatus (Duméril, Bibron and Duméril, 1854) is a colubrid with a distribution on the Atlantic versant from Veracruz and on the Pacific versant from western Chiapas southward to Costa Rica (^{Heimes 2016}). In Mexico there are three subspecies: C. l. lineatus (Duméril, Bibron and Duméril, 1854), C. l. concolor (Cope, 1867) and C. l. dunni (Smith, 1942). This snake is recognized for its wide diet although having a preference for lizards though; In general, its diet includes toads, frogs, lizards, birds and their eggs, small mammals, snakes, and members of its own species (^{Pérez-Higareda et al. 2007}, Heimes 2016). Here, we present a new item in the diet of Conophis lineatus lineatus in Veracruz, México as well as a literature review of dietary items C. lineatus (sensu lato) where at least the genus of the prey is given (Table 1).

Table 1 List of dietary items recorded for Conophis lineatus. 

On 12 June 2014, around 11:00 h, we found an adult of Conophis lineatus preying an adult individual of common toad Incilius valliceps (Wiegmann, 1833) (Fig. 1a) in a deciduous forest fragment in the locality Tejeria (19°o8'59" N, 96° 13'11.2" W; WGS 84; elev. 5 m) municipality of Veracruz, Veracruz, Mexico. At the beginning of our observation, the snake was just starting to eat the toad from the head, as an antidepredatory method, the toad inflated its body, and the feeding process took about 30 min. The snake had a snout-vent length (SVL) of 870 mm. Subsequently, on 13 June 2014, around 9:00 h, in the same locality, we found an adult of C. lineatus (SVL=790 mm) eating a corpse of an adult of Smilisca bauidinii (Duméril and Bibron, 1841) (previously observed) in a remarkable state of decomposition (Fig. 1b).

Figure 1 Records of adult Conophis lineatus prédation events in Veracruz, México. a. on an adult Incilius valliceps b. eating a corpse of adult of Smilisca bauidinii 

For the first observation, we determined the toad species based on two criteria: (1) distribution, which suggest two potential species Incilius valliceps and Rhinella horribilis (Wiegmann, 1833) (^{Oliver et al. 2009}), (2) the prey had short limbs, narrow head compared to the body, characteristics that R. horribilis does not possess (^{Oliver et al. 2009}). In the second case, we had previously observed the corpse and, based on its spotted dorsal pattern and the bars on the forelimbs on a bluish-green background, we determined the identity as S. baudinii (^{Duellman, 2001}).

Amphibians are an important part of trophic webs, being predators of a great variety of species, as well as prey to a large group of animals (^{Duellman and Trueb 1994}). Smilisca baudinii has been reported in several cases of prey-predator interactions with snakes (e.g. ^{Aguilar-López et al. 2019}), as well as other vertebrates (e.g. ^{Vásquez-Cruz 2020}). Nevertheless, few cases of predation have been reported in Incilius valliceps (e.g. ^{Avalos-Vela and Vásquez-Cruz 2018}), as in other bufonid species (e.g. ^{Hernández-Gallegos et al. 2019}). It is suggested that the secretion from the glands of certain bufonids causes nausea in vertebrates, shortness of breath, and muscle paralysis, and may even lead to death (e.g. ^{Shine and Wiens 2010}).

This represents the first report of predator-prey interaction between Conophis lineatus and Incilius valliceps and the second record of Smilisca baudinii as prey of C. lineatus (Greding 1972). Furthermore, this is the first case of C. lineatus as scavenger. Conophis lineatus is a snake with a wide range of prey species (Table 1), however, it shows preference for lizards of the family Teidae (^{Stafford and Henderson 2006}), likely because these lizards are very abundant. Our observation of C. lineatus as a scavenger suggests a low selectivity, considering any species that it manages to catch as a potential prey.