TRAP CATCH RESULTS

All trap catches are recorded as the traps are serviced and the tallies are summarised in the tables below. Catch rates increased initially as the management area was extended, and then as trap density was increased and traps and lures improved. Catch rates are now approximately constant as residents have been removed and invaders are caught. Detailed results indicate that most pests are now caught near the boundaries.

Stoat trap lines were installed from 2003 to 2006. Rat traps were installed in the 650 hectare core area in 2005 and 2007. Intensive possum trapping began in the core area in September 2010. In 2014 and 2015, additional possum traps were installed on trap lines S2 – S9, P1 and P2.

Stoats are the most numerous mustelids in the forest.  Weasels prefer a more open habitat and are caught at the forest edges. There are few ferrets in Northland (their favourite prey, rabbits, are not abundant) and only three have been caught by the Trust in Puketi.

All the rats caught in the forest are ship rats, Rattus rattus. Norway rats, R. norvegicus, may occasionally be caught at the forest edges but they are difficult to identify from the deteriorated remains in a trap and rat species are not recorded. Mice, Mus musculus and hedgehogs, Erinaceus europaeus are known to predate native invetebrates and the nests of ground-nesting birds but are not targeted at this stage. Mice are a bycatch in rat traps throughout and hedgehogs are a bycatch in mustelid traps at the forest edges.

Summary of Trapping Results 2003 to 2018:

Year Stoat Cat Weasel Ferret Rat Hedgehog Possum Mice
2003 47 6 2 1 74 5 8 0
2004 54 22 3 0 399 28 58 2
2005 78 18 4 1 538 29 41 0
2006 148 17 7 0 2189 121 368 120
2007 177 23 10 0 1369 77 83 0
2008 112 19 9 0 2914 79 414 88
2009 163 12 8 0 3497 60 459 73
2010 169 24 5 0 3258 52 1013 149
2011 200 39 10 0 3569 61 1321 360
2012 211 35 12 1 2936 61 1182 415
2013 176 24 16 0 3643 34 1236 327
2014 296 24 12 0 4669 42 2334 355
2015 133 40 9 0 3707 24 2706 302
2016 157 41 9 0 4472 16 3090 500
2017 205 27 5 0 3880 39 2765 293
2018 150 38 7 0 3332 41 2200 310
Total 2476 409 128 3 44446 769 19278 3294

Monthly Trapping Results 2018:

Month Stoat Cat Weasel Ferret Rat Hedgehog Possum Mice
January 54 6 0 0 348 5 333 2
February 2 1 0 0 126 2 118 4
March 2 4 0 0 227 4 156 10
April 8 3 1 0 288 3 224 27
May 10 5 1 0 657 5 227 161
June 0 0 0 0 240 0 42 49
July 14 4 0 0 400 7 139 11
August 16 0 4 0 303 3 169 21
September 1 0 0 0 94 0 114 8
October 4 1 0 0 194 2 92 6
November 5 11 1 0 186 5 272 8
December 34 3 0 0 269 5 314 3

Monthly Trapping Results 2019:

Month Stoat Cat Weasel Ferret Rat Hedgehog Possum Mice
January 57 3 0 0 282 15 275 4
February 0 1 0 0 176 3 154 11
March 9 2 0 0 226 7 86 19
April 5 3 0 0 320 11 164 49
May 7 4 1 0 554 6 322 105
June 4 1 0 0 215 12 174 94
July 17 5 1 0 467 5 205 40
August 8 4 0 0 412 2 135 30
September 1 1 0 0 157 0 142 14
October 4 9 2 0 392 1 64 15