Cottontail Rabbits in Relation to Trees and Farm Crops

by David E. Lantz

TREE PROTECTION.

WASHES.

Many devices for protecting trees from rabbits have been recommended, the majority of which are paints, smears, or washes supposed to be distasteful to the animals. Many are not sufficiently permanent to afford protection for an entire winter, and most of those that are lasting are injurious to trees. Coal tar, pine tar, tarred paper, and oils, under certain conditions, are dangerous to young trees. Carbolic acid and other volatile substances afford only temporary protection, and must be renewed too often to warrant their use. Bitter substances, like commercial aloes and quassia, are useless against rabbits.

The most promising simple washes for protecting large trees from rabbits are those containing lime mixed with sulphur or copperas in various combinations. Lime alone is not sufficiently permanent, especially where much rain falls. When mixed with sufficient copperas it has a deep green color and sticks much better. The lime-sulphur wash commonly used to destroy San Jose scale in winter has often proved successful as a rabbit repellent, but its lack of adhesive qualities often makes it fail. The defects may be partly corrected by mixing salt, soap, or a cheap glue with the lime and sulphur while the wash is still hot.

A poisoned wash of starch and glycerin, tried during the winter of 1913-14 in Idaho by a field agent of the Biological Survey, gave excellent results in protecting young orchards from jack rabbits, and would probably be equally effective where cottontails are concerned. The wash is prepared as follows:

Dissolve 1 ounce of strychnine (sulphate) in 3 quarts of boiling water. Dissolve 1/2 pound of laundry starch in 1 pint of cold water. Pour the starch into the vessel containing the strychnine and boil the mixture a short time until it is clear, adding 6 ounces of glycerin and stirring thoroughly. When it is cool enough apply with a paint brush to the tree trunks.

The glycerin and starch adhere well and form a thin coating to the bark. Rabbits attacking the trees will be quickly killed. In the Idaho experiments none of the trees were damaged badly enough to affect their growth and all the rabbits in the orchards were destroyed. The method is well worth trying; but care should be taken not to endanger domestic animals.

MECHANICAL CONTRIVANCES.

Among the best mechanical contrivances for protecting trees from rabbits are cylinders of woven wire netting. Poultry netting of 1-inch mesh, made of No. 20 galvanized wire, will answer every requirement. Rolls 18 inches wide are used for cottontails, and the material is cut into 1-foot lengths. One of the sections is rolled into cylindrical shape about the trunk of each tree and fastened at several places by bending and twisting the projecting ends of wire. No other fastening is needed, but stakes or spreaders may be used to prevent rabbits from pressing the wire against the bark and doing injury through the meshes. These guards should be left on the trunks, and will last as long as the trees require protection. The cost of material is less than 2 cents for each tree. These protectors may vary in size to suit the requirements of any particular locality or kind of tree. They may be adapted to protection from the larger rabbits by using wider rolls and to protection from both meadow mice and rabbits by using wire of finer mesh and by pressing the lower edges into the ground.

Veneer and other forms of wooden protectors are popular, and have several advantages when used for cottontail rabbits. When left permanently upon the trees, however, they furnish retreats for insect pests. For this reason they should be removed each spring. While the labor of removing and replacing them is considerable, they have the advantage when pressed well into the soil of protecting from both mice and rabbits. They cost from 60 cents a hundred upward, and are much superior to building paper or newspaper wrappings. The writer has known instances where rabbits tore wrappings of building paper from apple trees and in a single night injured hundreds. "Gunny-sack" and other cloth wrappings well tied on are effective protectors. Cornstalks furnish a cheap material for orchard protection when cut into lengths of 18 to 20 inches, split, and tied with the flat side against the tree, so as fully to cover the trunk. However, they last but one season and putting them in place involves much labor.