Snakes
A rare viper hybrid recorded in the Borjomi valley
Herpetology Notes reports an adult viper from the Borjomi valley with intermediate characters. The authors treat it as a hybrid, not a third species.
On 7 May 2025, in the Borjomi valley on the upper Mtkvari (Kura), observers recorded an adult viper that combined characters of Caucasus viper and nose-horned viper. The account was published in Herpetology Notes on 10 June 2026. The authors call it the first documented adult resembling the old name Vipera pontica, and the first such record from Georgia. They do not treat it as a species of its own. Reptiles.ge did not see the snake; this page follows their paper.
What happened?
The observation was at 10:45 on 7 May, in the Borjomi valley in Samtskhe — Javakheti. The authors place the site in the upper Kura valley, above 800 m. That morning they had already found five adult nose-horned vipers at the same place. The presumed hybrid was first basking at a forest edge, then again close to a nose-horned viper.
They describe the animal as a possible adult male. Snout–vent length was 447 mm, tail 61 mm, total 508 mm. No specimen was collected; identification rests on field notes and photographs. The paper has no DNA from this individual.
What is Vipera pontica?
The name Vipera pontica was given in 1990 to two juveniles from the Çoruh valley in Artvin, northeastern Türkiye. The taxon has been disputed ever since. Genomic studies cited in this paper treat those snakes as rare hybrids between Caucasus viper (Vipera kaznakovi) and nose-horned viper (Vipera ammodytes transcaucasiana) — not as a separate lineage.
The Borjomi record extends this putative hybrid form about 150 km east of the type locality. An unusual specimen from Gori was described in 1983; the authors leave its status uncertain and do not rest this observation on it.
What characters did it show?
The snake had an upturned but hornless snout, fragmented head scalation, intermediate ventral and subcaudal counts, a mixed dorsal zigzag, and a bicoloured tail tip. The authors call this a combination of diagnostic traits from both parental species.
They argue that such a coordinated mix is not explained by a single anomaly or by local variation, and that it fits an F1 hybrid. A later backcross is not excluded without genetic data. They consider involvement of Vipera berus barani unlikely: the species is not known from Georgia.
What does this mean for the atlas?
This is not a third viper species. The paper leaves V. pontica in the synonymy of both parents. On this atlas Georgian nose-horned vipers are Vipera ammodytes, subspecies transcaucasiana; the type locality is Borjomi. The 2026 checklist takes the same line.
The authors describe a narrow contact zone in the Borjomi valley: Caucasus viper in moister meadow and forest-edge habitat, nose-horned viper on rocky slopes. Where those microhabitats meet, rare hybridisation can occur. Both parents are venomous. This page does not assign a separate risk to the hybrid. If you meet a viper, keep your distance and do not pick it up. For a bite, call 112. The snakes hub and the species profiles remain the main record; news only adds this paper’s context.
