After hiking up swampy and muddy ground, I reached an area where the terrain became incredibly flat, much less wet, and covered with somewhat uniformly dull leaf litter. As I kept walking I noticed a small but stout snake fleeing out of the corner of my eye. I was excited to see the strange body proportion with a camouflaged glittering copper hue, immediately recognizing that I had not seen this species before. While scrambling after the snake and doubting its coloration I teased myself with the possibility of it being a Xenodon, which I have so longed to find. Xenodon includes striking color patterns that mimic coral snakes, the fer-de-lance, and even a Bothriopsis-like turquoise green! They flatten the neck defensively similar to the behavior of a hognose snake (Heterodon sp.)… but enough about Xenodon until I find one in the wild to write a blog post about. After securing the snake for a few photos, it was identified as a yellowbelly snake (Coniophanes fissidens). This species belongs to the subfamily Dipsadinae of colubrid snakes and is most closely related other leaf litter-dwelling snakes such as Rhadinaea, Tantalophis, and Amastridium.
Little about the ecology and behavior is known about the genus Coniophanes, and some species prove to be quite rare. In fact, this individual turned out to be a new record for Selva Verde. Coniophanes are commonly known as the black-striped snakes, named after dark striped patterns on the dorsum. These marking can be very faint as in C. fissidens, and I erroneously diagnosed it as C. bipunctatus because of its dual-spotted ventral patterning. They are a small but well-built genus, most reaching no more than 30-50 centimeters in length. The yellowbelly snake is capable of breaking off its tail when restrained, much as a glass lizard or skink does escape predation. Many individuals are encountered with severed tails, though this snake’s tail appeared to be entirely intact. Coniophanes feeds on a wide range of prey items including lizards, frogs, small snakes, invertebrates, and lizard and frog eggs. They tend to be secretive due to their semi-fossorial nature, and although I cannot confirm whether this snake was active at night or simply disturbed, C. fissidens has been described as having both diurnal and nocturnal habits.
Photographed after disturbance