Thamnodynastes strigatus ( Guenther , 1858)

enezes, Frederico de Alcantara, Abegg, Arthur Diesel, Silva, Bruno Rocha da, ranco, Francisco Luis & Feio, Renato Neves, 2018, Composition and natural history of the snakes from the Parque Estadual da Serra do Papagaio, southern Minas Gerais, Serra da Mantiqueira, Brazil, ZooKeys 797, pp. 117-160 : 117

Thamnodynastes strigatus ( Guenther, 1858) Figure 4F

Natural history notes.

Species of medium size (n = 15), nocturnal and terrestrial ( Marques et al. 2001, Barbo et al. 2011). The species was frequently found in November, December, and January. Ten individuals were observed resting during the day between 9:00 and 15:00 h; nine were in open areas and one on a forest border. Three individuals were found active at 22:00 h, foraging on the margin of a marsh with intense anuran vocal activity. Bernarde et al. (2000a) also observed this aggregation in T. strigatus in a permanent pond in Parque Estadual da Mata dos Godoy, Londrina, Paraná State. A juvenile was collected at 15:00 h while crossing an unpaved road after heavy rain. An adult was observed, also during the day (9:00 h), as it had captured by the leg and was attempting to prey on a Leptodactylus sp. Histological features of the retina of T. strigatus (i.e., presence of cones, but absence of rods) ( Hauzman et al. 2014) along with activity data obtained in captivity (Torello-Vieira and Marques 2017) reinforce the idea this snake exhibits significant activity during the day. Of the seven individuals examined, three presented stomach contents: lizard scales (in a young individual), a Physalaemus sp., and a Rhinella sp. (this last one also showed traces of an unidentified exoskeleton - possibly a secondary prey). Bernarde et al. (2000b) suggested T. strigatus is a generalist, feeding primarily on anurans (71.4%), but also rodents (14.3%), fish (3.6%), and lizards (3.6%). In regard to reproduction, one female (SVL = 585 mm; TL = 155 mm, collected in December) possessed 14 vitellogenic follicles and a young individual (SVL = 200mm; TL = 65 mm) was recorded in January. Barbo et al. (2011) mentioned observations of two females: one with 15 vitellogenic follicles in February and another one in November with 24 embryos. We could observe the following defensive behaviors for this species: cloacal discharge, head triangulation, body flattening, strike, and biting.

Altitudinal variation.

This species was found at a minimum of sea level and maximum of 2450 a.s.l. in Itatiaia National Park, state of Rio de Janeiro, Brazil ( Winkler et al. 2011). In this study, the maximum altitudinal record of the species was at 1730 m a.s.l., in the Baependi, MG.

Distribution and environment.

Southern, southeast, and northern Brazil ( Espírito Santo, Minas Gerais, Pará, Paraná, Rio de Janeiro, Santa Catarina, Rio Grande do Sul, Roraima and São Paulo), Paraguay, Uruguay and Argentina ( Franco and Ferreira 2003).