Mammal Spotlighting

Spotlighting surveys are a useful tool for monitoring mammals. The survey involves looking for nocturnal mammals. It usually involves walking or driving slowly along a line transect and looking for animals with a headtorch.

Why is mammal spotlighting useful?

Less stress for animals: Spotlight surveys don’t involve catching and handling mammals. Animals are often stressed if they are caught and handled by people.

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

What can mammal spotlighting monitor?

Spotlighting surveys can monitor the mammals that are active at night on Country. They are most often used to monitor species like possums, wallabies, kangaroos, gliders and koalas.

What can you learn?

• Biodiversity – what species live on Country
• Species Richness – how many different species live on Country
• Presence/absence – if and where species live on Country
• Activity  - how many of each species were seen during the survey. This can be used as an indicator of how large the population might be.
• Population size – how many of individuals live on Country. Only certain types of spotlighting surveys (e.g. line transects) can be used to estimate population size.

What can’t you learn?

Spotlighting can’t always tell you which species aren’t living on Country. This is because you might not see all the species of mammal on the night you do your survey or they might change their behaviour because you are in their habitat.

Spotlighting can’t tell you about the health of individual animals.

Using mammal spotlighting 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 scientific licences or animal ethics committee permits.

Nocturnal mammals need time to wake up and become active, so spotlighting surveys should always start at least 60 minutes after dusk.

Spotlighting survey shouldn’t be done when it is windy or rainy, or if the vegetation is very thick because it can be hard to see the animals in these conditions.

Temperature can affect how active the animals are – if it is unusually hot or cold for your area, it probably isn’t a good time to do the survey.

Lighting it up the animal with the edge of the circle of light and avoid shining the bright headtorch or spotlight at it an extended period of time to avoid blinding the animal. Once the animal has been spotted and identified, move the light away from the animal. Red lights and dimmer switches can be used for extended observation, but shouldn’t be used when searching as you will have reduced visibility.

Mammal Spotlighting with Line Transects

Nocturnal mammals can be monitored by spotlighting along line transects. This data can be used to estimate population sizes or activity indices. These surveys can be used to monitor lots of different species of nocturnal mammal, or can be used to target a specific species of mammal.

Usually these surveys are done on foot, but cars be used for some species of wallabies and kangaroos.

If you are interested in finding out where a specific species lives, then your sites can be in their preferred habitat. If you are interested in all of the nocturnal mammals on Country, then you sites need to be spread across all of the major habitat types.

To estimate population size, there need to be lots of detections of each species, the transects need to be surveyed multiple nights in a row, and the transects need to be in all of the major habitat types found on Country. To see if there are changes in the population over size, the survey should be done every 1-2 years at the same time of year or in the same season.

You can learn more about using this method in the Standard Operating Procedure Mammal Spotlighting Survey with Line Transects. 

Koala monitoring with line transects

Koalas can be monitored by spotlighting along line transects to estimate population sizes, activity indices or presence/absence of Koala populations. Unlike most other Australian mammals, this survey can be done at night with spotlights or during the day when Koalas can be seen resting in trees.

You can learn more about using this method in the Things We CareAbout page and in the Standard Operating Procedure for Koala Monitoring with Line Transects.