Abstract
There are 16 species of Philodryas snakes widely distributed in South America biomes. 1 Philodryas spp are non-front-fanged and have grooved posterior maxillary teeth and Duvernoy’s venom glands. 2 Although bites by most species have not been well documented, a few species have caused medically significant envenomation. For example, there is evidence of mild erythema, pain, and widespread ecchymoses after P olfersii and P patagoniensis envenoming.2,3 The experimental biological activities of some Philodryas venoms are similar to that of several pit vipers (eg, Bothrops spp). 3 For that reason, the effects of bites by Philodryas spp have occasionally been misdiagnosed by medical staff as Bothrops. Some patients presenting to Brazilian hospitals with confirmed Philodryas bites are incorrectly treated with antibothropic serum. 4 Currently, there is no specific antivenom medication for Philodryas envenomation.
These images were taken while trekking 2 d after a fire event, on a sunny day in February in the National Park of Brasilia, Brazil (15°44'20.93''S, 47°55'33.74''O), a park highly frequented by tourists. At 1300, we observed an alert Paraguayan green racer Philodryas nattereri (Figure 1) with its body, except for the head, inside a termitarium (Figure 2). In the Brazilian savanna biome, temperatures vary greatly within a single day (differences of up to 50°C have been recorded), and interestingly, fire events are part of the ecological dynamics. Behavioral information about neotropical snakes is scarce, but we know that species that live in regions with direct sunlight and little vegetation cover need some physiological and/or behavioral adaptations to survive in hostile conditions. Termitaria can be a safe place for neotropical snakes, offering camouflage and protection from the heat.
Adult specimen of Philodryas nattereri inside a termitarium photographed in February in the National Park of Brasilia, Brazil (15°44'20.93''S, 47°55'33.74''O). Photo: M. de-Carvalho
Details of Philodryas nattereri in alert using a termitarium as shelter, photographed in February in the National Park of Brasilia, Brazil (15°44'20.93''S, 47°55'33.74''O). Photo: M. de-Carvalho