Cannibalism, the consumption of conspecific individuals, is a behaviour widely recorded among animals (e.g., Fox, 1975; Polis, 1981), with records in several groups, including invertebrates (Polis and Farley, 1979; Baur, 1990), ray-finned fishes (Forney, 1976; Boldt et al., 2012), mammals (Bygott, 1972; Dorward, 2015), and reptiles (Bernarde and Abe, 2010; Barros et al., 2011). Among snakes, cannibalism reports were historically considered opportunistic events (e.g., Braz et al., 2006), commonly associated with dietary generalists (Polis and Myers, 1985). However, it has also been suggested that cannibalism in snakes has a high energy advantage for the cannibal (Cundall and Greene, 2000; Lourdais et al., 2005), a fact that can explain the relatively high frequency of these behaviours in several families (e.g., Boidae – Barros et al., 2011; Colubridae – Wiseman et al., 2019; Dipsadidae – Morais et al., 2020; Elapidae – Maritz et al., 2019; Viperidae – Freiria et al., 2006).

The mid-sized dipsadid snake Philodryas nattereri (Steindachner, 1870) is a species widely distributed in open areas of South America (Guedes et al., 2014). It is diurnal, terricolous, shows sexual dimorphism with females being larger than males (Passos et al., 2014), and its trophic ecology is one of the best-

known aspects of its natural history. Its generalist diet (Sales et al., 2020) includes primarily vertebrates, mainly lizards (Vitt, 1980), but also anurans (Guedes et al., 2018), mammals (Mesquita et al., 2010), birds (Mesquita et al., 2011), and snakes (Coelho-Lima et al., 2019). Nevertheless, up to now there was no record of cannibalism for this species. In this report, we describe the first case of P. nattereri preying a conspecific individual.

On 17 January 2018 at approximately 13:00 h, during fieldwork at Moita dos Porcos, Caetité Municipality, Bahia State, northeastern Brazil (14.1581°S, 42.5172°W, elevation 1022 m), we collected a female P. nattereri (snout–vent length, SVL = 831 mm; tail length, TL = 328 mm, Fig. 1) in a high-elevation Cerrado habitat dominated by grasses, with few trees and shrubs scattered, locally named campo sujo (Munhoz and Felfili, 2006). After being placed in a transport container, the snake regurgitated a juvenile conspecific (SVL = 315 mm, TL = 135 mm, Fig. 1). The prey was still alive after regurgitation, had multiple bite marks along its trunk and tail, and presented with peeling of dorsal scales consistent with the action of the predator’s palatal teeth (Fig. 2). Both specimens were properly euthanized with 5% lidocaine, fixed in 10% formalin, preserved in 70% ethanol, and deposited in the Coleção Herpetológica do Semiárido (CHSA) at the Universidade Federal Rural do Semi-Árido under accession numbers CHSA R 763 (predator) and CHSA R 764 (prey). The taxonomic determination of both specimens as P. nattereri was made by checking chromatic (typical brown colour pattern) and meristic (21–21–17 dorsal scale rows) diagnostic characters (Vanzolini et al., 1980).

Cannibalism has been previously recorded for other dipsadid snakes, including Erythrolamprus miliaris (Braz et al., 2006), Lygophis dilepis (Escalona, 2012), Oxyrhopus clathratus (Maia and Travaglia-Cardoso, 2017), Thamnodynastes phoenix (Morais et al., 2020), and even in Pseudablabes patagoniensis (previously Philodryas patagoniensis; Pontes et al., 2002; Hartmann

Herpetology Notes, volume 14: 843-846 (2021) (published online on 31 May 2021)

The short life of a juvenile neotropical snake: a record of cannibalism in Philodryas nattereri (Steindachner, 1870)

Alcéster Diego Coelho-Lima1,2,*, Dâmela Teixeira Cardoso2,3, and Daniel Cunha Passos1,4

1 Laboratório de Ecologia e Comportamento Animal, Universidade Federal Rural do Semi-Árido, Mossoró, Rio Grande do Norte 59625-900, Brazil.

2 Laboratório de Ecologia do Semiárido, Departamento de Ciências Humanas, Universidade do Estado da Bahia, Caetité, Bahia 46400-000, Brazil.

3 Laboratório de Estudo Animal, Departamento de Ciências Humanas, Universidade do Estado da Bahia, Caetité, Bahia 46400-000, Brazil.

4 Departamento de Biociências, Centro de Ciências Biológicas e da Saúde, Universidade Federal Rural do Semi-Árido, Mossoró, Rio Grande do Norte 59625-900, Brazil.

* Corresponding author. E-mail: alcester.coelho@ufersa.edu.br

© 2021 by Herpetology Notes. Open Access by CC BY-NC-ND 4.0.

Alcéster Diego Coelho-Lima et al.844

and Marques, 2005; Melo-Sampaio et al. 2020). Although ophiophagous behaviour had already been documented in P. nattereri (Oxybelis aeneus – Mesquita and Borges-Nojosa, 2009; Leptodeira annulata – Guedes, 2017; Oxyrhopus trigeminus – Coelho-Lima et al., 2019; Lygophis dilepis – Sales et al., 2020), the present record is the first case of cannibalism reported for this species.

In cannibalism, predatory individuals are generally larger than their prey (Polis, 1981) and in nature, cannibalism is an important source of mortality for several species, which may have density-dependent effects in cases of low resource availability or in contexts of high intraspecific competition (Siqueira and Rocha, 2008; Maritz et al., 2019). On the other hand, a lot of cannibalism happens in captivity, either between neonates or between parents and their young, possibly influenced by the environmental stress to which captive snakes are subjected (Cardoso-Junior et al., 1990; Braz et al., 2006; Maia and Travaglia-

Cardoso, 2017). Although cannibalism in snakes sometimes occurs between adult individuals (e.g., Capella et al., 2011), mothers are well known to ingest their non-viable eggs or neonates (Mitchell and Groves, 1993), and maternal cannibalism may be a beneficial strategy to obtain energy after the period of high reproductive demand (Lourdais et al., 2005; Mociño-Deloya et al., 2009).

The event reported herein included a female P. nattereri much larger than the minimum reproductive size reported for the species (Mesquita et al., 2011) and a small juvenile (Passos et al., 2014). Likely explanations include that a larger individual simply fed on a smaller conspecific (following the general trend noted by Polis, 1981), or that this event constitutes maternal cannibalism (see Lourdais et al., 2005; Mociño-Deloya et al., 2009). However, since the relatedness of the involved individuals is unknown, it is not possible to determine the actual scenario.

Until quite recently, ophiophagy in P. nattereri had

Figure 1. Adult female (above) and juvenile (below) Philodryas nattereri from Caetité, Bahia, Brazil. The juvenile (CHSA R 764) was preyed upon by the adult (CHSA R 763).

been considered occasional (Mesquita and Borges-Nojosa, 2009; Guedes, 2017) but the most recent records (Coelho-Lima et al., 2019; Sales et al., 2020) suggest that ophiophagy is more common in P. nattereri than thought, as has been suggested for other snakes (Maritz et al., 2019). Our finding expands the knowledge on the trophic ecology in Philodryas, and we hope that this record contributes to push forward the understanding on behavioural ecology of neotropical snakes.

Acknowledgments. We thank Rhamon Malheiro, Bruna Moura and Vitória Santos for their help during our fieldwork, Guilherme Souza, resident of Moita dos Porcos locality, for the receptivity and logistical support during field activities, Lander Alves for assistance with the phytosociological description of the area, Paulo Machado for his critical review of a previous version of this manuscript, and Daniela Pareja Mejía and the anonymous reviewer for the valuable suggestions in our text. We also thank Instituto Chico Mendes de Conservação da Biodiversidade for authorizing the zoological material collection license (license number 9292-1). ADCL thanks FAPERN and CAPES (Finance Code – 001) for providing a graduate (masters) scholarship.

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Accepted by Daniela Pareja Mejía