Herpetology Notes, volume 10: 619-620 (2017) (published online on 10 November 2017)

Thanatosis (death feigning) in the crucifer (Wied-Neuwied, 1821)

Diêgo Alves Teles1,*, Adonias Aphoena Martins Teixeira1 and João Antonio de Araujo Filho1

Amphibians display several defense mechanisms against predators, including fleeing, immobility, and thanatosis (Toledo and Haddad, 2009). The latter, also known as death-feigning, occurs when the assumes a posture that makes it appear dead, perhaps when it is under attack by a predator. It differs from shrinking, a behaviour during which a remains motionless and, almost without exception, has its eyes closed, fore- and hind limbs bent and close to the body, and in some instances including body arching and ventral flexing of the head (Toledo et al., 2010). Thanatosis has been reported for at least 16 families of (Toledo et al., 2010), including the family Bufonidae, where it is primarily reported in the genera Rhinella, Osornophryne, and Dendrophryniscus (Toledo et al., 2010; Escobar-Lasso and Gónzalez-Duran, 2012). Rhinella crucifer is a medium-sized (maximum snout–vent length 75.2 mm) nocturnal bufonid (Fig. 1A) that occurs in the Atlantic Forest remnants of eight Brazilian states (Bahia, Ceará, Espírito Santo, Minas Gerais, Paraíba, Pernambuco, Rio de Janeiro, Sergipe; Frost, 2016). We here describe thanatosis in R. crucifer for the first time. Daily observations were made during field surveys (ca. 0900–1000 h) on 1–6 September 2016, in the wildlife reserve Reserva Particular do Patrimônio Natural Engenho Gargaú, an area of Atlantic Forest in Santa Rita Municipality, Paraíba State, (ca. 7.1139º S, 34.9778º W; datum SAD 69). When manipulated, four individuals turned their ventral region up, with eyes

1 Programa de Pós-Graduação em Ciências Biológicas (Zoologia), Laboratório/Coleção de Herpetologia, Universidade Federal da Paraíba – UFPB, Cidade Universitária, Campus I, João Pessoa, Paraíba 58059-900, Figure 1. Individual of Rhinella crucifer (A) in normal position Brazil and (B, C) displaying the defensive behaviour of thanatosis * Corresponding author e-mail: [email protected] after manipulation. Photos by J.A. Araujo Filho. 620 Diêgo Alves Teles et al. open, arms upward, and legs upward and closed (Fig. Acknowledgments. We thank S.C. Ribeiro for contributing 1B,C). They remained in that position for about 4 min, the pre-peer review for this paper. We also thank the Conselho after which they returned to their typical posture by Nacional de Desenvolvimento Científico e Tecnológico – CNPq for a research fellowship to DAT and JAAF, and the Coordenação themselves. de Aperfeiçoamento da Pessoa de Nível Superior – CAPES for a Thanatosis as a defensive behaviour is probably research fellowship to AAMT. effective against predators that do not consume dead prey. This behaviour is more common in frog species References that do not have toxins, which is not the case for Rhinella (see Toledo et al., 2010). We postulate that Escobar-Lasso, S., Gónzalez-Duran, G.A. (2012): Strategies employed by three neotropical frogs (Amphibia: Anura) to avoid in R. crucifer thanatosis may be an additional, active predation. Herpetology Notes 5: 79–84. defence to augment the potential effects of its toxin. The Frost, D.R. (2016): Rhinella crucifer. Species of appearance of thanatosis observed here was similar to the World: an Online Reference. Version 6.0. Accessed on that described for other bufonids of the genus Rhinella 10 September 2016. Electronic database accessible at http:// (Toledo et al., 2010; Escobar-Lasso and Gónzalez- research.amnh.org/herpetology/amphibia/index.html. Duran, 2012). Since we recorded this defensive Toledo, L.F., Haddad, C.F.B. (2009): Colors and some morphological mechanism in the morning, we also suggest that this traits as defensive mechanisms in anurans. International Journal of Zoology 910892: 1–12. type of behaviour may possibly be presented by anurans Toledo, L.F., Sazima, I., Haddad, C.F.B. (2010): Is it all death when they are disturbed by potential predators outside feigning? Case in anurans. Journal of Natural History 44: 1979– of their usual activity cycle. Our observation is the first 1988. record of this defensive behaviour for R. crucifer and the fourth record for the genus Rhinella.

Accepted by Hinrich Kaiser