Spotlight & Listen Surveys for Frogs

Spotlight and listen surveys are a useful tool for monitoring frogs. The survey involves looking for frogs that are active and listening for frogs that are calling. It can also involve call playback, which means playing pre-recorded frog calls and then listening to see if any frogs in the environment respond by calling.

Why are spotlight & listen surveys helpful?

Less stress for animals: Spotlight and listen surveys don’t involve catching and handling frogs. Animals are often stressed if they are caught and handled by people. Handling frogs can also spread disease, such as Chytrid fungus which can kill frogs.

Inexpensive: Spotlight and listen surveys don’t need highly specialised or expensive equipment. Some headtorches can be over $200 but cheaper headtorches can still be used.

Quick and flexible: Spotlight and listen surveys don’t require much effort and can be done quickly and opportunistically when the weather conditions are suitable.

What can spotlight & listen surveys monitor?

Spotlight and listen surveys can monitor the frog species that are active and calling on Country.

What can you learn?

• Biodiversity – what species of frog live on Country
• Species richness – how many different species of frog live on Country
• Presence/absence – if and where frog species live on Country
• Occupancy - If enough surveys are done at different places on Country, the presence/absence data can be used to estimate occupancy. This type of modelling helps to work how many places really have frog species, even if they weren’t seen or heard at every site. This can be used as an indicator of how large the population might be and if is getting smaller/bigger over time.
• Activity – how many frogs are seen/heard during a survey. This can be used as an indicator of how large a population might be and if is getting smaller/bigger over time.

What can’t you learn?

• Population size  – the number of calls heard or frogs seen doesn’t always tell you how many animals are living there.
• Which species aren’t living on Country - some species of frog might not be calling when you do your survey, they might live in a different habitat type, or might change their behaviour because you are in their habitat.

Using spotlight & listen surveys the Right-way

REMEMBER! Any time you do work that might disturb or interfere with native animals and vegetation, particularly threatened species, you need to check with the state authorities to see if you need any approvals, such as licences or animal ethics committee permits.

The best way to detect frog species is to do this survey:

• at night
• in suitable habitat (around or in waterbodies)
• peak active and calling periods (breeding season)
• in suitable weather conditions (warm, wet nights and still or light wind conditions)
• multiple times throughout the year

It is important that the frogs are correctly identified. Use reference materials like frog ID books, and take photos and recordings of frogs during the survey so you can double check the identification. It is also useful to get people to help on a survey who have experience with identifying frogs, particularly from frog calls.

A daytime visit to your survey site(s) can help you locate the best habitat to survey, the best way to access the site at night, and if you are planning to use transects, to mark out the survey points every 50 metres with reflective flagging tape or similar.

Frog biodiversity monitoring

Frogs can be monitored with spotlight and listen surveys to find out frog biodiversity, species richness, presence/absence, occupancy and activity. Plan to do this survey when most of the species are active and calling, and/or do the survey several times throughout the year and/or do the survey in several different habitat types.

You can learn more about using spotlight & listen survey to monitor frog biodiversity on the Things We Care About page and in the Standard Operating Procedure Spotlight & Listen Surveys for Frogs

Targeted frog species monitoring

If you are interested in a specific species of frog, you can use spotlight and listen surveys to find out presence/absence, occupancy and activity. Plan to do this survey when the target species is active and calling (breeding season) and in its preferred habitat.

You can learn more about using spotlight & listen survey to monitor frogs on the Things We Care About page and in the Standard Operating Procedure Spotlight & Listen Surveys for Frogs

Cane Toad monitoring

If you are interested in monitoring Cane Toads, you can use spotlight and listen surveys to find out about presence/absence, occupancy and activity. Plan to do this survey when Cane Toads are active and calling (breeding season) and when they are easiest to find in their preferred habitat (e.g. waterbodies that hold water all year round).

You can learn more about using spotlight & listen survey to monitor Cane Toads on the Things We Worry About page and in the Standard Operating Procedure Spotlight & Listen Surveys for Frogs