How to stop rabbits, hares eating trees

Press, 13 July 1984, Page 27

How to stop rabbits, hares eating trees

Two methods of treating newly planted shelter trees to discourage hares and rabbits from browsing on them are to be tested by the Forest Research Institute in trial plots which will be planted soon on a North Canterbury site. The trials will compare the relative effectiveness of a commercially obtainable preparation and a simple, “home-made” repellant developed by the staff of the F.RJ. at Rangiora. The conimercial preparation, based on the fungicide, thiram, is a liquid which may be painted or sprayed on young trees.

The F.R.I. repellent is a solid, to be smeared on the trees by hand, as a very thin film. The ingredients are mutton fat and kerosene, in a recommended

proportion of 10 parts by volume of mutton fat to one part of kerosene. The cost is negligible, and no complicated preparation is necessary. The fat is heated until it melts, then removed from the heat so that the kerosene can be stirred in. The mixture is then left in a cool place, and soon as as it solidifies it is ready for use. According to an F.R.I. spokesman the mixture will keep for years, and need not be stored in refrigeration. Its effectiveness has not yet been tested experimentally, but, according to the spokesman, trial plots at Omarama which were treated with the mixture suffered less damage from browsing than untreated plots in the same rea. The North Canterbury

trial will attempt to quantify the effectiveness of the mixture, compare with it with the commerical product, and determine how long each remains effective in the field. A percentage of trees in the trial will be left untreated as a control.

The spokesman emphasised that the F.RJ. mixture should be handled with care, because overenthusiastic application could damage young trees. A very light smear, applied with gloved fingers, is recommended.

Ideally, the application should be done on a cold day, because if the mixture were softer than butter consistency it might brown off the needles of young conifers, he said. This would, however, not kill the trees.