Meet the coal black tree snake, a newly discovered species

The Herald Scotland

27-04-2025

In a study published in the peer-reviewed journal Zootaxa on April 4, Kraus described his trip to four different islands, each of which housed a not-yet-classified species of reptile. He was seeking to study groups of tree-dwelling snakes known as the Dendrelaphis genus, a group Kraus described in his research as "confusing" and "poorly understood."
On Sudest, he observed a shiny, large species of snake notable for its jet-black color, black eyes and white chin. While studying the species, which he spotted in ecologically diverse areas on the island from "rainforest to villages and gardens established by humans," Kraus witnessed the snake turn its predator, a hawk, into prey.
One of six of the elusive creatures that Kraus managed to track down was found wrapped around a goshawk (a hawk with a wingspan of up to 46 inches) that had apparently tried to attack, rendering it "immobile by the snake's enveloping defensive reaction."
So far, the snake, named for the Latin word that roughly means "coal black," has only been found on Sudest Island, though the study notes it could possibly exist on nearby small islands.
Three other new snake species identified
Kraus also identified new snake species endemic to three other Papua New Guinea islands: Misima Island, Rossel Island and Woodlark Island.
On Misima Island, he found more large snakes with white chins, black eyes and black coloring, though these slightly smaller 4-foot, 1-inch reptiles lacked the same lustrous sheen as the coal black tree snakes of Sudest.
Named Dendrelaphis atra, or the atra tree snake, after the Latin word for black, these snakes are described as having a "matte black" color that develops in adulthood. Before they reach maturity, says Kraus' study, they sport a more "gray brown" hue.
Also found in villages, gardens and rainforest ridges, the species was at first confused with the one found on Sudest before unique elements such as its size, color and scale pattern were studied. Uniquely, atra tree snakes were found in areas heavily developed by humans, such as on a mining site and near buildings.
As with the coal black tree snake, the atra tree snake has thus far only been found on its initial island of discovery, Misima.
Another new snake species has orange eyes
On Rossel Island, Kraus found Dendrelaphis melanarkys, or the black net tree snake. This 4-foot, 11-inch reptile is easier to differentiate thanks to its orange eyes, smooth dark scales with a net-like pattern and dark tongue color.
Named after the Greek words for "black" and "net," the species was again found to inhabit both the local rainforest and human-made facilities on the island, including the abandoned site of the former village of Bibikea. The species also has only been found on one island.
The Dendrelaphis roseni, or Rosen's tree snake, found on Woodlark Island, is the smallest of the newly discovered species, measuring only about 3 feet, 5 inches. Found only on Woodlark Island, the snake was named after Kraus' "late friend, snake ecologist and conservationist" Clark Rosen, said the study.
Like the atra tree snake, Rosen's tree snake is a lighter color in adolescence before developing its black pattern in adulthood. Also like the other species on nearby islands, the Rosen's tree snake is found in the rainforest, villages and gardens tended by humans.