The oral discs of anuran tadpoles are diverse and involved in feeding, sensing, and attaching to the substrate. The umbelliform oral discs in the tadpoles of the subfamily Megophryinae (Megophryidae) are highly specialized for feeding at the water surface and characterized by dorsally-oriented, laterally-expanded flaps decorated with arrays of papillae. The functionality of these oral discs remains understudied. Here, I report a hiding behaviour in Brachytarsophrys chuannanensis tadpoles, where the tadpoles attach themselves to a firm substrate underwater, using their oral disc as a suction cup. These tadpoles were positively buoyant when feeding at the water surface. If disturbed, they tried to hide underwater by attaching the oral disc to a solid substrate to prevent from floating up. The attachment was maintained with active buccal pumping, which reinforced the friction between oral disc and the substrate. Further observations suggest that the tadpoles gained positive buoyancy from air storage in their lungs, and they were negatively buoyant after deflating them. My results suggest that dorsally-oriented oral discs in Brachytarsophrys tadpoles can be used for substrate adhesion, which is likely an effective means to hide from potential threats or prevent passive displacement in the dynamic flow environment of mountain creeks.
The viability of many turtle species, including the European pond turtle (Emys orbicularis), is imperiled by nest depredation. Depredation rates of the E. orbicularis population in eastern Slovakia are high; therefore, we aimed to identify nest predators and to determine which sensory cues they use to find the nests. From the set of different experimental trials with artificial nests in the field, only the application of turtle-scented water imitating the female migration path to the nesting site suggested potential predation of turtle nests driven by olfactory cues. Although we did not observe depredation of the installed artificial nests, we identified badgers (Meles meles), wildcats (Felis silvestris) and wild boars (Sus scrofa) as potential predators. Our results also imply that the use of chemical repellents should be considered for nest protection of the study species in the Tajba National Nature Reserve.
Morelet’s crocodile (Crocodylus moreletii) has recovered from past overexploitation but it is necessary to continue monitoring its status in the context of the sustainable harvest (ranching) planned for the species in Mexico. We obtained new information on the population status of C. moreletii at the boundaries of two protected natural areas in southeastern Mexico that serve as the basis for long-term monitoring. From September 2014–March 2018 we carried out nocturnal sampling and captured crocodiles along four selected routes representing different water body types. For each crocodile observed we collected information on the localization, environment and the individual. We observed a mean of 0.8 ± 0.3 crocodiles/km, with significant differences detected among routes. We captured 54 crocodiles (sex ratio: 1.7 ♂ : 1 ♀). Except for subadults, crocodiles were more frequently associated with medium flooded forest than with other types of vegetation. Adults were observed at deeper sites than other age classes. Observation sites of yearlings have higher salinity than those of neonates, juveniles, and adults. The results show a dynamic population with all size classes in a suitable habitat for its growth.
We present a case of predation of the spider Tidarren sisyphoides (Walckenaer, 1841) (Araneae: Theridiidae) on the ringneck coffee snake Ninia diademata Baird & Girard, 1853 in the state of Veracruz, Mexico, being the first instance where a spider of the genus Tidarren preys upon a reptile and the second predator reported for N. diademata.
We present a herpetological survey from a secondary Atlantic Forest fragment in Itanhaem municipality, southeastern Brazil. Field expeditions were conducted over 21 months, at Estacao Ambiental Sao Camilo. We recorded 22 species of amphibians and 18 of reptiles using three different sampling methods, pitfall traps, visual encounter survey and occasional encounter. No species is listed in the Brazilian list of endangered species, or in the IUCN red list. This secondary fragment harbour common species for Atlantic Forest, however, the endemism rate for Amphibians is 86%, which means these “coldspots” are important to consider as an alternative for conservation in Atlantic Forest.
Species of Paleosuchus have small body size and well-developed osteoderms over most of the body and tail, features that make its skin commercially unattractive. Thus, these species are subject to little hunting pressure when compared to the black or the spectacled caimans. However, hunting for bushmeat is not as selective as hunting for skins, andpoaching of Paleosuchus species is widely practiced throughout Amazon. This study presents an overview of poaching of Paleosuchus species in northern Brazilian Amazon by reporting local densities close to urban areas and recording subsistence and commercial hunting events. In this study, very few caimans were counted, only seven individuals along 66.0 km of water bodies surveyed. Ten hunted specimens were also recorded, apparently a large number considering the short time time this survey was conducted. Hunters had to travel long distances to find game, including caiman. This, coupled to the many cases of hunting recorded in the short period of time we surveyed these areas, suggests that the vicinity of settlements is over-hunted which explains the lower than normal densities found in this study.
Java is one of Indonesia’s most densely populated islands with many long-neglected environmental issues, including snake envenomation and biodiversity decline. In an effort to promote snake conservation and mitigate human-snake encounters, particularly those resulting in snakebite, we here provide information on the composition, distribution, and habitat types of snakes on Java based on a 2013–2019 survey. A total of 54 snake species from 12 families were encountered. Our surveys indicate that several species, some venomous, inhabit human-populated areas. The likelihood of conflict between humans and snakes is primarily caused by the proximity of snake habitat to urbanized areas, resulting in high levels of human-snake interactions. We suggest that research should be prioritized on synergistic survey efforts, not only to elucidate the diversity and distribution of snakes on Java, but also to aid in efforts to avoid snakebite, produce suitable antivenoms, and promote snake conservation.
We studied thermoregulation in Pacific Knobbed Iguanas (Microlophus occipitalis Peters 1871) in a sand dune ecosystem in coastal Ecuador. During the daily activity period, operative temperatures (Te) on sand or on debris in direct sunlight far exceeded the upper limit of the lizard thermoregulatory setpoint range reported for Microlophus(Tset-max= 40∘C). However, the operative temperatures of other microhabitats, whether in shade or in direct sunlight, were largely below Tset-max throughout most of the day. Average lizard surface temperatures, as recorded remotely using radiotelemetry, increased rapidly during late morning, exceeded Tset-min-min (36∘C) slightly between roughly 1000–1600 hr, and thereafter declined slowly into the evening and early morning hours of the following day. Lizards maintained Tswithin the Tset range about 66% of the time when it would be permitted by mean Te. We did not detect differences in thermal biology between males or females.
For the first time we report predation events on evolutionarily distinct and globally endangered Nasikabatrachus sahyadrensis Biju and Bossuyt, 2003.
