Rotoiti Ramblings Winter 2016
The trend of very low catch numbers is continuing however trapping is not always a good measure of predator numbers and unfortunately this is reflected in the DOC tracking tunnel results from May: All lines-rat 27%, mouse 2%, St Arnaud range lines-rat 32%, mouse 1% and Big Bush lines-rat 10%, mouse 3%. Mustelids were 0% across all lines. For effective control these need to be below 5%.
FOR was unsuccessful in the 2016 funding application to Kiwis for Kiwi. We aimed to complete the translocation of great spotted kiwi from unprotected areas to the RNRP Mainland Island. The initial partial translocation was done by DOC in 2004 and 2006 and the population is currently estimated to be around 29 with 18 of these being unrelated founders. The ideal founding number is 40 individuals so we were hoping to source another 20 to ensure a strong genetic base for this population and to enable better quality research to be carried out in this easily accessible site.
Over the last month we have been targeting feral cats on Mt Robert road in the National Park using 12 Havahart live- capture cages baited with fresh rabbit. These extended from the West Bay campground to the Mt Robert car park at 880 m and were checked daily by 5 members who all hold current firearms licenses and were approved by DOC to dispatch catches utilizing a head shot with a .22 calibre rifle. This resulted in the capture of 5 feral cats, 9 possums and 3 weka (released unharmed). You may be surprised at the number of possums caught, especially as there are sentinel traps up the road which caught nothing. The literature shows that possums are more easily caught on the ground and they readily scavenge carcases including deer, pigs, their own, plus rabbit which is a favourite. Of course we cannot use kill- traps on the ground because of weka however we are going to install raised-set Timms traps (1.2 m above the ground) near Coldwater Hut on the Whisky line and at the beginning of the Speargrass line as all recent possum catches have been scavenged.
This exercise was in addition to our normal feral cat trapping operation comprising 24 Havahart cages set on private property in the village and on surrounding farmland adjacent to the National Park. This has been in operation for the last 3 years and from June 2015 to May 2016 we have caught 133 feral cats, 113 of these having been caught in the 3 month period of March to May this year, mostly in the Tophouse Rd area. 4 obvious domestic cats were released. The best time to target this operation is spring when breeding is about to start and autumn when a lot of “innocent” juveniles are about. It is important to accompany rural feral cat control with effective rodent control (and rabbit control if you are a farmer) as research shows rodents and rabbits are the main prey items and removal of this apex predator has been shown to lead to an increase in rats, the top predator of our forest birds.
There has been a lot of research done on feral cats in New Zealand, a good summary can be found in Craig Gillies’ paper, http://www.tandfonline.com/doi/pdf/10.1080/03014223.2001.9517648 . Identification of prey items was done by scat analysis as well as intestinal contents, not my idea of pleasant research but a more reliable indicator than most urban cat research which relies on prey brought home. For urban cat control research it is worth doing a New Zealand search using Google Scholar, a lot has been learned however it has to be said that much of it is a repeat of work already done (but different locality) and arguably a waste of valuable research funding and ratepayers money.
Feral Cat Trapping.
Between June 16 and July 10, at a DOC request, 5 of us set out a trapping line of 12 live capture traps on Mt Robert Road baited with wild rabbit meat. Over the next 33 days we checked the traps each day. 9 of the traps were successful with 10 possums, 1 stoat, 6 feral cats, and 4 weka being caught. The weka were released unharmed and well fed. I was very surprised at the number of feral cats we caught at such a bleak time of year, all of which were caught in the bush, as against open grassland. The highest cat was caught at the top of Mt Robert Road which I estimate at over 1000 m above sea level.
Hi all.On Friday Nik and Emma took Sim and myself up to Coldwater to check Whisky trap line.Nik showed his boating skills as he picked us up at the jetty at the western end of Kerr Bay as there was a cold stormy southerly coming down the lake.It was a very rough and cold trip. Emma took charge of the boat as the lake smoothed out.
We did a bait change on all possums sentinels and stoat traps and re baited all Timms cat traps.
Catches for the day 7 Rats 2 possums 1 stoat and 1 cat. The cat was caught in No3 trap Mt Robert side of Whisky Falls. We have caught 3 cats since they have been installed, 1 at Coldwater in a ground based Timms, 1 at Whisky in a ground based Timms and 1 which is attached to a tree on a platform. We have 4 platform type Timms and 2 ground based Timms installed on the Whisky line
A cold and windy walk but very enjoyable.