Chew cards are a simple tool used to help identify the presence of predators on your property. Learn about how to use them, download our guide on how to make your own or buy some ready made from our shop.
What are they used for?
Chew cards are cards filled with a lure that is attractive to predators. They can be used to identify rats, stoats, possums and hedgehogs. Animals chew the card and allow you to identify what predators are present.
Tracking tunnels or wax tags for possums can also be used. Chew cards are a useful way of identifying where predators are on your property and where to place your traps or bait stations.
When should chew cards be used?
Chew cards are an easy way to identify what predators you have and where they are active on your property. The bite marks on the card allow you to determine what animal has chewed the card so you can select the appropriate tools to target them. Places where you find activity on chews cards are often good places to place traps or bait stations.
You can use chew cards as a way to monitor the effectiveness of your predator control programme (read our monitoring page).
What’s in them — do they contain toxins?
Chew cards are non-toxic and include a lure to attract introduced predators.
Depending on the brand you purchase the formula may be different. Some use a highly palatable formulation while others use a long life lures, both are in paste form and are non-toxic. If kept in a warm dry place the shelf life can be up to 12 months.
Where can I get chew cards?
You can buy packs of chew cards on our online shop or you can make your own with corflute and peanut butter – we’ve created a simple guide:
Where I should place them?
Start by placing them in areas where you have seen evidence of introduced predators. Along a fence line, near compost or rubbish bins, at the base of trees are a good place to start.
Predators will only investigate food – and therefore a trap – in places where they feel safe, so not in an open space. For comprehensive instructions on setting up chew card lines over large land areas, see page 28 of DOC’s A practical guide to trapping.
How do I install them?
Before installing them name and/or number each card so you can record individual results. Installation depends on which product you purchase. In most cases you nail or screw them to a tree or post. Instructions are generally provided with the product or check out the manufacturer’s website for more detailed instructions.
If you have created your own chew cards fold in half and leave the top flap open approximately 45°. Nail 30cm above ground level.
As a general rule the suggestion is to leave chew cards out for seven days before interpreting results. We recommend you check the instructions provided by the manufacturer. Remove chew cards after you have finished.
How do I read the results?
If predators are interacting with the chew cards you will see bite marks on the card. Unique bite or tooth mark impressions on the chew card accurately indicate what predator is present.
Instructions provided with the product (or on the manufacturer’s website) will help you to identify what predators you have. Or you can use Manaaki Whenua’s “Guide to the interpretation of animal tooth impressions” to identify which animal has been biting.
What next?
Once you know what predators are present you can buy a trap and get trapping. Do some research to find the trap that best suits your budget and capability. Some people are very comfortable handling predators and others are not. For that very reason there is a variety of different trap options available on the market today. See our trapping best practice section.
If you are using chew cards to monitor the difference you are making then you should record your results so you can compare them to future results. Record information such as location and date, what activity, what weather was like. Having a record means you can see how results compare year to year.
Read our section on Tracking Cards and Tunnels