Automated acoustic monitoring of amphibians

Automated acoustic monitoring of amphibians

Singapore

Local amphibians including...

Horned Toad

(Megophrys nasuta)

The IUCN Status

LC Least Concern
NT
VU
EN
CR
EW
EX Extinct

Short-legged Dwarf Toad

(Pelophryne signata)

The IUCN Status

LC Least Concern
NT Near Threatened
VU
EN
CR
EW
EX Extinct

The challenge

When the song is inaudible
No matter the species, proper conservation planning relies on having an accurate estimate of the population sizes of wildlife. One of the most accurate ways to estimate the population size of amphibians is through acoustic monitoring, because amphibians call to attract mates and to signal that they occupy the territory they are in. Acoustic techniques have been used for a long time across the world to collect information of vocalising animals like birds, amphibians and insects. The trouble with collecting vocalisations by amphibians is that their activity and the audibility of their calls is affected by the structure of the environment. We don’t fully understand how habitat structures and urban noise alters amphibian calling and the audibility of their calls. Furthermore, we know very little about amphibians in Southeast Asia as this kind of data isn’t readily available.

The goal

Listening more closely to Singapore’s acoustic landscape
'
Singapore is an ideal “field site” to collect data on amphibian vocalisations because it is an urbanised landscape that nonetheless supports rich biodiversity. The overall aim of the project is to assess amphibian population dynamics in Singapore by establishing a pilot study of the acoustic landscape in five semi-natural to natural areas. These areas are: Bukit Batok Nature park, Windsor, Fern Valley, Thompson Nature Park and Bukit Timah Nature Reserve. The latest advances in computer technology allow researchers to collect data and identify calls more easily, making data collection and analysis a lot more efficient. One development is the automated acoustic monitoring. Calls collected remotely are automatically classified into a specific species group, so that researchers can continue studying data about that species. Survey stations can also automatically collect information on temperature and humidity levels, so that we can better understand how these factors affect amphibian calling behaviour and their population dynamics.

Our role

A pilot project to better understand our amphibians
'
WRS fully supports Eva Catharina Madelene Karlsson from NUS on this pilot project as it will give us valuable insights into threatened amphibian species in Singapore and how they respond to urban noise, disturbances in the landscape and ongoing development across the city-state. Our support enables the research team to acquire and set up the equipment across various survey stations situated in the field.

The impact

The first automated acoustic monitoring project in Asia
The survey stations will provide long-term information on population fluctuations, including the effects that invasive species have on native amphibians. With this data, a comprehensive conservation management plan can be crafted to protect threatened amphibian species across Singapore. The units that will be situated in the field can remain in these areas for the long-term and will become the first long-term automated acoustic monitoring project in an urban setting in Asia, providing a permanent record of population fluctuations and species turnover.