What we do
Animal pests such as possums, mustelids, feral cats and pigs are the biggest threats to biodiversity.
Our main activities are animal and plant pest control by trapping and baiting, pest monitoring and maintenance of tracks to allow access for trapping and baiting.
Pest animal control
Animal pests such as possums, mustelids, feral cats and pigs have a significant negative impact on the flora and fauna. Possums pose a serious threat to our forests and native wildlife by destroying plants and birds’ nests, eating birds’ eggs and invertebrates, and competing with other species for food. Mustelids eat seeds, eggs, chicks and insects and feral cats eat reptiles and birds and pigs disturb roots and destroy the understory, and carry diseases like kauri dieback.
Trapping programme
A network of nine bait and trap lines have been established in the conservation area. Traps are also positioned around the houses. Specific traps are used to target each pest species:
DOC200 style traps - targets stoats and rats.
DOC250 - targeting ferrets.
AT220 and Timms traps - targeting possums.
Other traps for feral cats, hedgehogs and mice.
Attracting the pest animals
A range of baits is used to entice the pest into the trap. We are currently using eggs, terracotta lures, fish, and dried rabbit. It’s important to change the type of bait from time to time so that the animals don’t become trap shy.
The traps are checked and reset if required once a month from May to October then fortnightly from November to April.
Baiting programme
Our baiting programme targets rats and possums. Bait stations are mounted on trees along the tracks. A pulse baiting programme is used. This means fresh bait is laid then checked and baits replenished after one to two weeks. At the end of week four the baits are removed so that the bait doesn’t degrade and deter the pests in the future.
Making it easy for the pests
We follow best practice guidelines to optimise the effectiveness of the baiting programme. Bait stations are mounted at an optimal height on a tree or fence post which has a natural ramp for the animal to access. Attractant is spread on the access to entice the animal.
Pest Plant Control
Wilding pines are a significant threat to biodiversity in the Mana Manu conservation area - just as they are all over the Coromandel.
Aggressive weeds
Fast growing maritime or cluster pine (Pinus pinaster) are common as are Pinus radiata. These prolific growers take root easily as the seeds blow many kilometres. Maritime or cluster pine was introduced to Coromandel in the 1920-30s. Commercial forests of Pinus radiata nearby provide a constant seed source. Wilding pines require constant monitoring and intervention to ensure the trees are removed before they establish.
Battling the pines
Mature pine trees can become very dense quickly as the wind spreads their seeds. They take the sun, water and nutrients that other plants need and can quickly crowd out regenerating native bush.
Each landowner takes care of the wilding pines on their own property. Methods used include hand pulling, hand sawing, mechanical felling, and poisoning.
Monitoring
Monitoring of target pest animals over time is an essential activity to determine whether we are making a difference and to help guide our control work.
We monitor
bait consumption
pest animal kills
relative abundance of rodents or mustelids
relative abundance of birds by bird counts
Bait consumption
The type and quantity of bait laid at each bait station is recorded on the TrapNZ app and entered into a database. Monitoring bait consumption allows us to determine areas which may have a greater abundance of pests and therefore indicate areas where more effort needs to be employed.
Pest animal kills
The number of pest animal kills in traps are monitored ongoingly. These are also recorded on the TrapNZ app. Monitoring trap catches over time allows us to determine the effectiveness of our traps and trapping programme.
Tracking tunnels
We undertake monitoring for the presence of rats and mice using tracking tunnels before and after bait runs. Tracking tunnels are a sampling method used to measure the presence of target pest species. The tunnels are placed along tracking lines which are spaced out throughout the conservation area.
Each tunnel has an attractant (we use peanut butter) and pre-inked paper. The animal walks on the paper to reach the attractant. The tunnels are left in the bush overnight then collected the next day. Volunteers identify the footprints and count the number of prints for each species.
Bird counts
We have recently introduced five-minute bird counts (5MBC) as a method of monitoring the relative abundance of different species of birds. Five-minute bird counts are an established index measure from which the density of bird populations can be inferred.
Volunteers are positioned at locations around the conservation. They listen and look for birds then record the bird species and numbers of each seen and heard during a five minute period.
Five-minute bird counts are undertaken four times a year. They give us an indication of the overall success of all our pest control programmes and the progress towards meeting our ultimate goal of providing a habitat where threatened and endangered birds and wildlife will thrive. We are currently working on building a baseline of species present and their numbers.
Maintaining access
A safe and accessible track network is an essential part of maintaining our traps and bait stations.
The main access points are the four private roads that provide an entrance to the properties in the conservation area: Horongahere ROW, Kaipapaka ROW, plus two others. Traps are dotted along the roads as well as on the tracks which have been built to allow traps and bait stations to be spread throughout the conservation area.
The roads form an important part of the trapping network as they provide the easiest means for accessing traps. The roads are maintained by the property owners.
Bait lines follow the tracks
A network of tracks was established around 2010 - the most significant of these being an old bulldozer track on the north side of the Kaipapaka valley which dates back to the farming days. Nine bait lines have been laid out. These are mostly in the Kaipapaka valley.
Track clearing by hand
The tracks are maintained by hand. The battle against gorse and pampas, which capitalise on any areas where sunlight gets through the canopy, is ongoing. Mānuka and other low growing plants need to be cut back regularly to keep the tracks open and accessible.