# Cryptic Painted Frog Successfully Establishes Breeding Population on Pulau Ubin Youth volunteers use bioacoustics to monitor the rare frog's successful adaptation to artificial habitats. - **Source:** [The Straits Times – Singapore](https://www.straitstimes.com/singapore) - **Published:** 2026-11-08 - **Topic:** [science](https://brifing.si/c/science) - **Original article:** - **On Brifing:** https://brifing.si/s/f2d3b584-059c-4306-bc29-8c6dde51551c ## Successful Species Relocation The vulnerable Cryptic Painted Frog has established a breeding population on Pulau Ubin following its introduction in 2024. Native to Singapore's mainland primary rainforests, the species was previously confined to Bukit Timah and Central Catchment reserves. This relocation effort aims to protect the frog from localized threats like disease and habitat degradation. ## Artificial Breeding Infrastructure Because the species relies on water-filled tree cavities for reproduction, which are rare in Pulau Ubin's secondary forests, NParks installed 21 artificial phytotelmata. These water-filled containers include PVC pipes and sticks to provide essential egg-laying surfaces. This infrastructure allows the arboreal frogs to breed effectively despite the lack of natural tree hollows. ## Bioacoustics Monitoring Methodology A team of five youth volunteers monitored the frogs over six months using non-invasive bioacoustics and motion-detection cameras. They placed four audio recorders across the site to track mating calls. This method allowed researchers to observe the nocturnal, elusive species without causing physical disturbance or interfering with their natural mating behaviors. ## Sound and Breeding Correlation Data analysis using Kaleidoscope software revealed that male calling activity strongly correlates with egg counts. The frog's distinct high-pitched chirp, typically occurring at frequencies between 2 and 4 kHz, serves as a reliable indicator of reproductive success. This confirms that sound tracking is an effective, non-invasive tool for assessing population health. ## Environmental Impact Factors The study identified that calling activity is more closely linked to rainfall and humidity levels than to air temperature. Researchers observed a peak in reproductive activity during the week of July 13, 2026, with 37 eggs recorded. These findings provide critical insights into the specific environmental conditions required for the species' survival. ## Ecological Indicator Species The Cryptic Painted Frog acts as a vital natural indicator of ecosystem health due to its sensitive skin, which easily absorbs environmental pollutants. Its presence and successful mating signify that forest habitats are clean and thriving. Monitoring this species helps conservationists evaluate the overall biodiversity and environmental quality of the Pulau Ubin site. ## Youth Engagement in Conservation The project was conducted under the Youth Stewards for Nature programme, involving students from the Asian School of the Environment. By collecting data and identifying patterns, these volunteers bridged the gap between public awareness and hands-on scientific work. This initiative helps cultivate the next generation of wildlife conservation practitioners in Singapore. ## Future Conservation Strategy Establishing populations in multiple locations is a strategic move to reduce the risk of extinction from single events like extreme weather or disease. By successfully introducing the frogs to Pulau Ubin, NParks has demonstrated a scalable model for species recovery. Continued monitoring will ensure the long-term viability of this vulnerable amphibian population. ## Sources covering this story - https://www.straitstimes.com/singapore/environment/how-is-the-cryptic-painted-frog-settling-in-to-its-new-pulau-ubin-home-its-a-singing-success — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._