Fence guards stilts which are nesting at Lake Tekapo

Press, 30 August 1980, Page 14

Fence guards stilts which are nesting at Lake Tekapo

From the Royal Forest and Bird Protection Society

The people of Canterbury who have contributed generously to the Royal Forest and Bird Protection Society’s “Save the Black Stilts” appeal will be gratified to know that the electrified predator-proof fence (described in Oliver Riddell’s article in “The Press” of April 23) has been erected at Mailbox Inlet on Lake Tekapo and was tested just before Conservation Week. The presence of the first black stilt, several pied stilts, together with banded dotterels, paradise ducks, and spurwing plovers inside the enclosed area has been a great encouragement; the birds had not been deterred from returning to the region by the fencing. At present, the area enclosed is being systematically trapped to clear any feral cats, ferrets, rats, hedgehogs, or other animals which may have been caught inside the netting when it was erected. The fence consists of tall, tanalised pine posts to which is stapled a set of 12)-gauge, high-tensile steel wires spaced to support two strips of galvanised wire netting. The lower, rat-proof.

half-inch mesh is buried 6in to Sin below ground; the upper cat-proof and ferretproof strip, with two-inch mesh, is carried above an electrified wire stood off to prevent rats or ferrets climbing from ground level. There are parallel electrified wires above and below this to prevent damage to the fence from stock. The final guard, about 51ft above ground, is another electrified wire placed so that a wild cat attempting to jump on to the fence would be thrown off. Its design was the result of consultation between Mr R. J. Pierce, of Otago University, and technicians of the physics department of the University of Canterbury, the New Zealand Agricultural Engineering Institute, and the Wildlife Service. An interesting secondaryproblem is the protection of a portion of the fence which is inundated for several months of each year by the slightly corrosive, waters of Lake tekapo. A scheme for cathodic protection is being investigated, to keep the wire polarised during this period which falls outside the birds’ breeding season

when the battery is required to energise the anti-pre-dation wires.

The chosen site is adjacent to another unprotected nesting site which will serve as a control during the initial stages of the experiment as the scheme is intended to produce valid scientific data on breeding success in the region. Should it prove successful, then a succession of similar sites of increasing difficulty will be fenced out in turn. The Royal Forest and Bird Protection Society as a whole is budgeting for a sum not far short of $lOO,OOO over the coming decade. Hundreds of individuals, several organisations, and members of the business community which have given time, money, and equipment have made this venture possible in a lastditch attempt to preserve in the wild one of New Zealand’s most beautiful birds and the world’s rarest wader. There will be a work of substantial practical value to. display to members of the International Union for the Conservation of Nature’s conference at Christchurch in October next year.