10 Apr 2014

Mast Seeding and Predators

From Our Changing World, 9:20 pm on 10 April 2014

Stu Thorne with a trap that has caught a stoat, and Gillian Crombie with a tracking tunnel

Stu Thorne with a trap that has caught a stoat, and Gillian Crombie with a tracking tunnel (all images: A. Ballance)

Stu Thorne with a trap that has caught a stoat, and Gillian Crombie with a tracking tunnelThe Department of Conservation (DOC) recently declared a Battle for the Birds, in anticipation of a mass seeding event in New Zealand’s southern beech forests this summer. The mast seeding could lead to an explosion in predator numbers next summer, and conservation groups such as the newly-formed Matukituki Charitable Trust are monitoring the situation to work out what response they will need to mount.

Alison Ballance joins the Trust’s founder Gillian Crombie, and volunteer and ex-DOC ranger Stu Thorne, on the Rob Roy Glacier track (left) just off the West Matukituki Valley, an hour’s drive from Wanaka.

In September 2013, the Trust began a monitoring and trapping programme in the valley, using tracking tunnels to monitor mice, rat and stoat numbers, beech seed funnels to collect and measure beech seeding. They are also adding to the existing network of stoat traps run by DOC.

Depending on the results of the latest monitoring the Trust and DOC will decide whether an extended network of traps is sufficient to deal with the expected explosion in stoat numbers, or whether the best solution will be an aerial drop of 1080, which is the main tool DOC will be using to counter the expected stoat plague.