Monitoring is one of the most important aspects of feral animal control. It evaluates the impacts on the invasive animal, the effectiveness of the control program, and whether resources are being properly allocated.
Monitoring feral animals can take many forms but is any process where data about feral animal populations, their behaviours, and their impacts is collected, analysed and interpreted.
Common forms of monitoring for foxes and feral cats are camera-trap surveys, spotlight surveys, track counts, trap–catch efforts, environmental DNA monitoring, and counts of wildlife or of livestock losses. For monitoring agricultural impacts, variables might be numbers of lambs reaching marking age, losses at the abattoir due to Sarcocystis, or unexpected pregnancy losses or barren ewes that may be due to Toxoplasmosis.
NSW Department of Primary Industries, the Centre for Invasive Species Solutions and partners have developed a useful free mapping, monitoring and reporting app called FeralScan. FeralScan allows anyone to report sightings or evidence of a feral animal and also helps individuals and groups privately record and map where control activities have been undertaken through the app or website.
Some monitoring techniques, in some states and territories, need ethics approval, especially if they are likely to change behaviour of animals or put them at risk. Permission is needed to undertake monitoring programs on land other than your own.
Useful Guides:
- Monitoring techniques for vertebrate pests: Feral Cats
- Monitoring techniques for vertebrate pests: Foxes
- A guide to surveying red foxes and feral cats in Australia
Motion cameras are a common monitoring tool. Photo: A. Bensen.
Track counts can be done on already sandy tracks, or sand can be brought in. Photo: National Wild Dog Action Plan.
Why monitor?
Monitoring feral animals or their impacts before and after implementing a management program is crucial for assessing effectiveness, making informed decisions, adapting strategies and preserving ecosystem health. Monitoring also supports evidence-based conservation practices and demonstrates the success of management efforts.
Pre-implementation monitoring:
- establishes a baseline understanding of the feral animal population and its impact on the environmental or agricultural assets you are wanting to protect
- acts as a reference for assessing the program’s effectiveness
- informs decisions about management strategies, allowing interventions to be tailored to specific ecosystem, landscape or production needs.
Post-implementation monitoring:
- evaluates the program’s success by comparing data to the baseline, revealing population changes, benefits to native species, livestock or other assets you are protecting
- supports adaptive management, so programs can be adjusted in response to unintended consequences or unexpected changes
- justifies resource allocation by demonstrating the real impact of feral animals and the positive outcomes of management
- highlights if the management program is not working as intended and that changes need to be made.
Long-term monitoring:
- tracks trends in feral animal populations and impacted assets such as threatened species or livestock
- aids decision-making about continued management or strategy modifications
- contributes to scientific understanding of ecological or agricultural interactions and informs broader conservation efforts.
Monitoring also assists people running programs to adhere to regulations, ethical guidelines and conservation goals.
Are you removing more pest animals than are being born? Photo: John Carnemolla.
Are you getting more lambs reaching marking and sale? Photo: Morgan Gronolt, Remote Area Planning and Development Board.
Monitoring techniques
Motion cameras
Motion or wildlife cameras are motioned-sensored and capture images or videos of animals including wildlife, foxes and feral cats that trigger the camera as they pass by. Wildlife cameras are strategically placed in the field to capture images of desired animals to assess changes in activity or abundance. Motion cameras can be checked manually (in the field) or online, with compatible cameras, via mobile or satellite reception.
Advantages:
- generally non-invasive, especially if not using lures
- provide visual evidence of species presence, behaviour and possibly numbers.
Limitations:
- limited to areas where cameras can be installed
- may miss species or animals that avoid camera locations
- larger programs can end up with a lot of photos to analyse, especially if cameras are not set properly and pick up a lot of vegetation or shaddow movement.
Spotlight surveys
Night-time surveys use spotlights to detect feral cats and foxes. Depending on conditions and how close one can get, foxes and feral cats may be identified by sight or from the shine of their reflective eyes.
Advantages:
- effective for nocturnal species
- provides immediate visual confirmation.
Limitations:
- limited to nocturnal hours and tracks or roads
- may not detect all individuals or between individuals
- labour-intensive
- can be intrusive on wildlife.
Track and scat identification
This method identifies and documents tracks (footprints) and scat (faeces) left by foxes and feral cats or impacted wildlife in the field.
Tracks are often counted on areas of soft soil or sand that was prepared beforehand by raking or dragging. Sand may even be brought in for track counts. Scat counts are less common, as identification can be more difficult without testing.
Advantages:
- non-invasive
- can provide information on species presence, diet and genetics.
Limitations:
- requires expertise in track and scat identification
- labour intensive
- abundance is difficult to calculate as it is hard to know if it is the same or different animal that made the track or scat
- may not always provide real-time data.
Trap–catch effort
Traps are set in the field to capture foxes and feral cats or impacted wildlife. Data on captures and trap effort are recorded.
Advantages:
- provide precise data on individual animals
- can inform population estimates.
Limitations:
- require specialised equipment and expertise
- can be costly and time consuming
- may stress or harm animals.
Environmental DNA (eDNA)
This method involves collecting environmental samples (e.g. water, soil, faeces) to detect traces of DNA shed by feral cats and foxes or targeted wildlife species.
Advantages:
- non-invasive
- can detect species presence, even if animals are not seen.
Limitations:
- requires laboratory analysis
- does not provide information on individual numbers or behaviour.
Wildlife or livestock taken
Monitoring examines losses of wildlife or livestock to assess the impact of foxes and feral cats. However, losses of wildlife are often more difficult to account for and assess than losses of livestock. Dead animals need to be found and reason for death identified.
Advantages:
- quantifies economic and ecological impact
- demonstrates direct evidence of predation if there is some contention of the cause of deaths.
Limitations:
- may not provide data on pest numbers
- is an indirect measure of presence.
FeralScan: community-driven science
Online apps and website platforms like FeralScan allow everyday people to report sightings, evidence and impacts of foxes and feral cats.
FeralScan is also used by many individuals and groups to privately manage and map the data from their group, i.e. lodge, map and report their sightings and control efforts and to be notified when a target pest is seen in their area.
Advantages:
- free, well-tested and supported
- large-scale data collection
- engages the whole community in management efforts
- fosters public awareness and investment
- allows private management groups to share and report on sightings and management.
Limitations:
- data quality can vary with input
- may require proper validation by experts in some cases.
Banner photo: Gill Basnett.
New technology, such as 4G and AI identification software is making monitoring using motion cameras even easier. Photo:National Feral Cat and Fox Management Coordination Program.
Spotlight counts along transects are a useful monitoring technique. Photo: C. Spencer.