Kleptoparasitism, or food theft, is seldom reported in wild populations of snakes. Here, we describe as case where two Red-tailed Coral Snakes, Micrurus mipartitus, were observed competing for the same caecilian prey, either Caecilia leucocephala or C. perdita. This took place at night in a rainforest habitat in Valle del Cauca Department, western Colombia. Upon our arrival, the battle had already started as the two coral snakes kept bite-holds on the caecilian. They continued biting the prey at different places on the anterior parts and tugging in opposite directions. The snakes also made rotations along the longitudinal axis as they maintained their bite-holds. Surprisingly, one snake also bit the body of the other snake once. After 17 minutes of observation, the losing coral snake released its bite-hold on the caecilian. The winner then moved away from the losing snake which did not follow. It is well-known that M. mipartitus and other coral snakes eat caecilians, but this is the first observation of kleptoparasitism in elapid snakes in the wild. It is considered likely that they rely on chemoreception when detecting caecilians, notably in this case as two coral snakes detected the same prey item. In general, kleptoparasitism may occur more frequently amongst snakes than indicated by the very few published cases considering that numerous cases from captivity are known.

We redescribe the type material of Phyllodactylus siamensis Boulenger, 1899, type species of the Southeast Asian gekkonid genus Dixonius Bauer, Good & Branch, 1997, using external morphology and cranial osteology. There is some evidence that the type series contains more than one species; we hence designate a lectotype in order to stabilize nomenclature and provide more precision on the geographical location of the type locality. Because the current concept of Dixonius siamensis auctorum is incomplete and composite, we provide a revised diagnosis based on the presently designated lectotype and a paralectotype from the same locality, as well as observations on new material from the type locality and the first photographs of live topotypical individuals. We regard Dixonius siamensis as probably geographically restricted to the Dong Phaya Yen mountain range in central Thailand, and the numerous published mentions of this species from outside this range likely refer to other or undescribed taxa. We treat Phyllodactylus burmanicus Annandale, 1905 from Tavoy, southern Myanmar, as a valid species, as Dixonius burmanicus comb. nov.

Color polymorphism is an important trait due to its role in defense strategies, feeding habits, environmental responses such as temperature regulation, and overall fitness. While the genetic basis of color polymorphism is well understood in mammals, it remains relatively understudied in non-avian reptiles. Vipera berus, the European adder, is the most widely distributed and northernmost terrestrial snake in the world. Similar to other European vipers, V. berus exhibits a range of dorsal color patterns spanning from zig-zag to complete melanism. However, a unique longitudinal dorsal stripe pattern was recently discovered in the isolated Gossa Island (∼45 km2) population of Norway, where approximately 5% of snakes exhibit this distinct pattern instead of the common dorsal zig-zag pattern. In this study, we investigated the genetic basis of the unique phenotype observed on Gossa by combining low-depth whole-genome shotgun sequencing and pairwise FST genome-scanning. We discovered a moderately sized, significantly differentiated genomic region containing five associated genes, including the premelanosome gene (PMEL) that encodes a well-known transmembrane glycoprotein that is a key component of melanosome organelles. We implicate a functionally relevant variant in the encoded premelanosome protein. Our results provide insight into the evolution and genetic basis of pigmentation of squamate reptiles using the unbiased approach of genome scanning, a method that has rarely been used in this context.

We describe six new species of burrowing lizards of the genus Riama Gray, 1858 from the high Andes of Ecuador. Their status as new species is confirmed based on their unique combination of molecular, meristic, hemipenial, and color pattern characteristics. The taxonomic revision is based on examination of 188 museum specimens, a phylogeographic analysis of 244 locality records, and 53 individuals of Riama sampled for molecular characters. With these additions, the number of Riama in Ecuador increases to 18.

In snakes, predatory attacks on oversized prey are not uncommon. Here, we describe an adult female Vipera berus that likely bit and intended to swallow an oversized young hare, Lepus europaeus. The estimated mass of the hare was about 10 times greater than that of the viper. The event took place in Denmark, on 10 August 2022. We suggest that the adder under these circumstances might have benefited from a large prey to gain maximum energy after likely having given birth. Greatly oversized prey items killed by snakes are poorly known in literature. Based on published and unpublished reports, we add to the knowledge of snakes’ killings and subsequently abandoning oversized prey items. It may be an underdocumented phenomenon.