Prepared by Hauraki Islands Branch of Forest & Bird & ARC
Leading Animal Pests on Hauraki Gulf Islands

Rats – particularly the ship rat (Rattus rattus). Has longer tail and bigger ears than other rats.
Is a very good climber and can get into ceiling and wall cavities.

Stoats & ferrets. Brownish, about size of small thin cat with slightly bushy tail.

Argentine Ants – Waiheke Island has an infestation. For further information look at: http://www.biosecurity.govt.nz/pests/argentine-ant/control or http://www.arc.govt.nz
or contact Deryn Dromgoole; Auckland Council Waiheke Biosecurity Officer (part-time; days available are Tuesday, Wednesday & Thursday 021948756 or 366-2000 x 8873))

Rabbits

Hedgehogs – Found both in gardens and the bush. Will eat ground laid eggs and fauna so is a threat to e.g. native lizards

Mynahs – also known as the Indian Mynah. Brownish/black bird with yellow beak and legs often seen on road and road verges. A prolific breeder and with an aggressive reputation in relation to other birds. They tend to roost in big flocks on particular trees.

Feral Cats – attacks many native species

Magpies – similar issues to mynahs
This management guideline only covers the first two animals pests as these have the most adverse effect on native birds and other native fauna.
People are encouraged to, also, control numbers of rabbits, hedgehogs and mynahs. If a neighbourhood has a mynah roosting tree it is recommended control be focused on the birds when they return to that tree in the evening. Please seek the advice of the Auckland Council Waiheke
Biosecurity Officer (details above) for setting up a control plan so there is no adverse impact on other non-target birds.
RAT CONTROL AND MANAGEMENT
Aiming for a significant reduction in rat numbers increases bird fledgling numbers significantly. An effective plan in small sections is to get your neighbours involved in joint or collective action.
The two leading control methods are trapping or baiting.
The best time to target rats is during winter, with the aim of reducing numbers to a minimum before spring breeding.

Trapping
Good method for small areas, for putting around house foundations to catch rats as they enter or leave a house cavity, or for properties where bait might endanger domestic pets or livestock. It is, however, labour intensive as you need to check the traps regularly to deal with dead animal remains. You, also, have to ensure that the trap is enclosed in a pet and bird-proof box or tunnel. It is less effective on a large property.
All rat traps should be kill traps to meet humane standards.
Using a grid system of putting out traps is the most effective control method in larger properties. Rats have a 50m range so traps need to be spaced that far apart.
Lures for rats include – peanut butter, chocolate, cheese, fruit, meat
The following is recommended for cost effectiveness and outcome. Where they can be purchased and cost is alongside the name of the trap.

T Rex Snap Trap (Placemakers (Michelle Civil can discuss your needs)); http://www.nopests.co.nz
; http://www.philproof.co.nz
)) Cost - $12.30

E-snap trap (Placemakers; http://www.nopests.co.nz
; http://www.pestrid.co.nz
; http://connovation.co.nz
) Cost - $10-$15
(Both traps are easy to set; have a handy place for bait, and need to be used under cover when outdoors.
The E-snap trap springs may last longer in coastal conditions)

Victor Professional snap trap (Placemakers) Cost - $6.75-$10
Fairly easy to set but the plastic setting area may wear after a time, wooden base will last longer if oiled before use, must be used under cover outdoors, larger rats may be able to escape

Ka Mate rat trap ( http://www.kamatetraps.com
ph 03-548-8871) Cost - $20
Recommended for boaties but can be used inside houses or under cover if outside. Fairly easy to set with built in safety catch, durable metal material
Baiting
Most effective method for larger properties.
All properties using baits, particularly Brodificoum, need signage at entrance. It’s a requirement on the label. Different baits are traded under varying names so read labels and discuss with retailer (Michelle
Civil at Placemakers can give advice).
All bait needs to be secured and enclosed within boxes or tunnels so the bait is eaten on site and not taken away, is kept dry, stops access by non-target animals, allows sign placement, and makes setting up a permanent bait network easier. ARC recommends Protecta Sidekick stations these can be purchased via www.nopests.co.nz
Other tunnels and stations are available from Placemakers. www.connovation.co.nz
or the Forest & Bird stall at the Saturday Waiheke Island Ostend market.
Best practice methodology for bait use is to use pulsing and rotating. Pulsing refers to cycled intermittent placing of bait stations Initial baiting can commence during winter until bait take reduces, then baiting every 6-8 weeks and ceasing in early autumn. Rotating refers to alternating types of bait every 3-6 months. Both pulsing and rotating help ensure the rat does not become bait shy or habituated to particular baits, it also reduces the possibility of secondary poisoning of non-target animals.
In larger areas bait laying in a grid system achieves the most effective control as it ensures there are no gaps. For rats a grid of 50m x 100m or 75m x 75m is recommended. In steep topography the choice is between following contours (sidling) or ridgelines (climbing). A compass or GPS and a hip chain can be used for measuring straight lines in bush. The route between bait stations would be marked with flagging tape and the stations should be numbered with a permanent marker.
If pet access to the stations is a concern then they should be attached at minimum height of 1.5m with rat access by a running board or stick placed against the post or tree. Otherwise place stations 30 cm above the ground. There is no difference in effectiveness amongst these differing placements.

Lay a station across, not along a gradient, so water doesn’t flow into it and dissolve bait.
If bait is never taken move the station to another site e.g. near fruiting trees (Puriri/karaka/citrus etc.)
Recommended relatively cheap baits include:
Brodifacoum (Trade Names include Pestoff, Talon ($9.45 at Placemakers)).
This is a second generation anticoagulant and tends to be stronger and faster acting as the rat can consume a lethal dose in one sitting, however it also has a longer half-life in the environment and can, therefore, accumulate in tissues creating a higher risk of secondary poisoning i.e. poses some risks to pets or other non-target species.
It tends to have a cereal formulation which can deteriorate quickly once outdoors and it is recommended sealing these pesticides inside a plastic bag before placing in the bait station
It can be easily accessed from either the Forest & Bird stall at the Saturday Waiheke Island, Ostend market (at good discount), or Placemakers.
Vitamin K is antidote for accidental poisoning.
Diphacinone (Trade Names include Ditrac or Ratabate)
This is a first generation anticoagulant. There is a low risk of secondary poisoning as it has a short half- life in the environment, it is not water soluble although it breaks down more slowly in soil. Rats need to consume continuously for up to five days to get a lethal dose so bait stations have to be full for this time period. It is now available in an extremely palatable paste that overcomes some of its disadvantages. It is, also, available enclosed in a wax shield for tree attachment.
It can ordered from www.connovation.co.nz
; phone: 09-273-4333
For maximum cost effectiveness (if rat numbers are high) the baiting management programme should start with a effective fast acting pesticide e.g. brodifacoum, followed with a maintenance programme using waxed or longer life bait.
Recommended more expensive bait include:
Cholecalciferol (e.g. Feracol®)
An acute poison which releases calcium leading to cardiac arrest or renal failure.
Low risk of secondary poisoning and only one dose is required. No bioaccumulation and degrades rapidly in the environment. Less toxic to avian species than some other poisons. However there is no antidote for cholecalciferol so need secure child/pet stations.
It can be ordered from www.connovation.co.nz
; phone: 09-273-4333
Please note that currently this toxin is not readily available in NZ due to hugely increased global price of the raw ingredient
Trapping
Unless you have the time to train a stoat dog (see http://www.arkinthepark.org.nz
) which has little adverse impact on the environment, this is still the most effective and cost effective method of controlling stoats, although they are difficult to trap
Lures for stoats include - fresh or dried rabbit meat, egg, fish, chicken necks, chocolate.
The only recommended trap for stoats is:

DOC 200 ( http://www.predatortraps.com
, haines.pallets@paradise.net.nz
; spearco67@yahoo.co.nz
) Cost - $50 (trap & single set tunnel)
For ferrets:

DOC 250
These humane traps are fairly easy to set especially if a separate setting tool is purchased. They are suitable for permanent positions but initially heavy to position without vehicle access. Low bi-catch risk.

The Weka safe DOC 200 may be safer around urban sites as the trap is set further back in the box.
Traps should be set at approximately 200m spacing along tracks and bush edges. They need to be checked regularly so access should be fairly easy. Stoats have large home ranges so complete area coverage is not necessary. Good trap placement is the key.
To protect birds over a breeding season, it may only be necessary to trap for the season. To protect endangered species traps may have to be set all year round.
Live traps need to be checked daily and other traps will need to be checked weekly/fortnightly from
December through to March and fortnightly to monthly for rest of the year dependent on catch rates.
Any pest management requires result monitoring. Rat tracking tunnels and ink pad/cards can be purchased for this purpose (Gotcha Traps http://www.gotchatraps.co.nz/index.html
) Tracca Kit (has guide to check prints of other pests or non-target animals) - www.connnovation.co.nz
). Monitoring should be planned for September, December and April to ascertain early season, mid-season and end of season. The mid-season result will allow you to adjust your baiting/trapping regime.
Mustelids are difficult to monitor and trap catch is a good indication of activity levels.