Read our Trappers Guide to Predator Free Port Hills for detailed information on the traps sold by the Summit Road Society.
Finding the best location for your trap(s) will depend on the type of trap you have and the predators you want to target. When placing traps, if children might come onto your property, make sure that they cannot reach the trigger mechanism, either by placing the trap out of reach e.g. mounted high enough on a tree, or by making sure it is inside a secure trap box which is designed so that children cannot reach inside.
To identify the best place to put traps, a good way to start is to place some chew cards around your property. These are cards impregnated with a lure which encourage pests to chew on them. The bite marks left behind can then be used to identify the pest animal. That way you can see which pests are a problem and where they are the most prevalent. Your local co-ordinator should be able to supply you with some chew cards and can give you some advice on how to use them.
Chew cards showing typical chew marks, from left to right: possum gnaw marks, stoat/hedgehog/cat puncture marks, rats chew entire sections of card, mice chew small sections of card (Halo)
An important aspect of achieving a Predator Free Port Hills is to coordinate our trapping efforts. We can do this by recording trap locations and the number and type of pests being caught.
Recording catches also means that we can see how much progress has been made, which helps with publicity and funding, but also keeps everyone informed and enthusiastic as we can see the collective results of the group.
Pest detection helps identify the types of pests that are present and to get a measure of pest activity. It can be done using tracking tunnels or you can simply look for animal scats i.e. poo, or toothmarks on fruit and nuts. Tracking tunnels will give a measure of changes in relative abundance over time.
A tracking tunnel is a run-through tunnel containing a pad that shows the footprints of animals that travel through the tunnel. A tracking pad can be made by placing two pieces of paper either side of a sponge soaked with a tracking medium like food colouring. As an animal passes through the tunnel it picks up the tracking medium on its feet, then, as it departs from the tunnel, it leaves a set of footprints on the papers. It is a non-destructive sampling technique so it does not impact the target species or, any non-target species.
Footprints left on the tracking papers can then be compared to pictures of tracks from different types of pests (see below).
These images show examples of tracking tunnels - a homemade tracking tunnel, top (DOC) and a commercial tracking tunnel, bottom (Science Learning Hub).
Check out this video for instructions on how to make your own tracking tunnel with materials from around the house. A great activity for the kids.
Examples of pest footprints (Pest Detective)
Possum scats top, and stoat scat middle left (Jaqui-nz, Nature Watch),
mouse and rat droppings middle right (Goddamn Bowtie, doctorwhogeneral.wikia.com);
possum damage to trees (DOC, Steele, Pest Detective)
One thing to consider is that some predators will peak in numbers and/or activity at certain times of the year. For example, stoat numbers peak in summer, but that peak is only for a very brief time and this is when many species of native birds appear to be most vulnerable.
Another thing to look for are animal scats. For example, stoat scats are black, long and thin, and usually are full of bones, feathers or fur, and 40-80mm long. Scats are often deposited as a 'marker' in prominent positions such as on top of logs or stones along travelling routes. The scats of ferrets and weasels are very similar, only differing in relative size. However, take care not to confuse these scats with blackish bird droppings - the contents of the droppings should identify the owner.
Possums also cause distinctive damage to vegetation. The Pest Detective is a great website for identifying pests if you are not sure.
Pest monitoring is a more systematic process that helps assess the prevalence of pests and predators over time. As it uses a systematic method, results can be compared over time and between locations. It involves the placing of tracking tunnels and chew cards at set points on a monitoring line. Tracking cards are usually placed out for one night, chew cards for 7 nights.
Predator Free Port Hills is currently undertaking monitoring in reserves in selected suburbs across the Port Hills.
To get in touch, please email Predator Free Port Hills or sign up via our website.