The hidden enemy

Forest and Bird, Issue 292, 1 May 1999, Page 43

The hidden enemy

— Stephen Westgate.

Getting rid of stoats is a critical step in making the environment safe for birds, writes STEPHEN WESTGATE. he impact of stoats is not immediately obvious — until suddenly it becomes apparent that birds which were once present are seldom seen or heard. Like all serial killers, stoats operative furtively and unseen. The extent to which they may be present and wreaking their unseen havoc is aptly demonstrated by the catch rate on the Okaihau (Northland) farm of Forest and Bird members Jan and June Wilson, adjoining the Puketi Forest. Brown teal were released on Ian and June’s property about three-and-a-half years ago. Since then, an intensive predator trapping regime has been maintained, which has resulted in a good survival rate of the brown teal, and some breeding success. Up to 50 tunnel traps are maintained on 80 hectares, along with various traps for feral cats. The results have been amazing. Prior to starting the trapping programme, the Wilsons had only seen two stoats in 15

years. Since then they have caught 97 stoats, five weasels, one ferret and 36 wild cats. The predator catch rate has been: Summer 1995-96 (traps only, no baits): 9 stoats, 5 wild cats. March 1996-97 (traps baited with rabbit): 43 stoats, 2 weasels, 14 wild cats. March 1997-8: 35 stoats, 2 weasels, 10 wild cats March-October 1998: 10 stoats, 1 weasel, 1 ferret, 7 wild cats. At peak times, three stoats a week have been caught over a two-month period (December 1996-January 1997). Ian Wilson sees this summer period as the time when stoats are spreading out, seeking new territories. Obviously, the reinvasion rate is incredibly high and continuous monitoring of the traps is essential, particularly over this period. The number of feral cats caught is also of great concern. With this number of serious predators caught on just one farm, the survival of some species of native birds on the mainland appears to be dependent on ‘mainland island’ refuges and on private property, where committed people like Ian and June Wilson are prepared to ‘make a

difference’.