Several researchers have reported the first sighting of an invasive frog species on Borneo island, Malaysia. The discovery occurred during a nighttime field study in April, part of efforts to expand the Kinabalu area within the UNESCO Global Geopark in Sabah.
According to a study published September 11 in the journal Check List, scientists were alerted by loud calls near a puddle and identified the source as dark-sided chorus frogs (Microhyla heymonsi). These frogs are described as “tiny, stocky, tear-shaped frog with a small, flattened head,” and are typically found across mainland Asia but had not previously been recorded on Borneo.
The team noted that these frogs were “very common but challenging to collect because they were hidden in the tall grasses” and relatively small. Photographs from the fieldwork show several captured specimens.
Researchers believe that human activity likely led to their introduction: “Given this new population was recorded from a highly disturbed agricultural area, we believe that the frogs were accidentally introduced into Borneo through anthropogenic activities, possibly through the import of farming materials,” researchers said.
Observations indicated that the species is already established locally. “The dark-sided chorus frogs appeared ‘to be well established and not a recent introduction into the area as the frogs were abundant and explosive breeding was taking place after the rains,’” according to the study.
The ecological impact of this new presence remains unclear. The research urges vigilance among other herpetologists: “Other herpetologists working in Borneo should keep a lookout when conducting field surveys to monitor the presence of this species to keep track of their spread,” it stated. “Based on what is known regarding the ecology of the species and its adaptability to human-modified landscapes, its spread across Borneo appears inevitable and can be expected in the near-future.”
Borneo is shared by Brunei, Indonesia, and Malaysia and is recognized for its rich biodiversity. The research team included Evan Quah, Aderina Dukit, Alvinus Joseph, and Paul Imbun.
