An Investigation of Animal Damage Associated with Maple Syrup Production

An increase in the use of plastic tubing systems to collect sap from sugar maples (Acer saccharum) has allowed syrup producers to boost production in recent years, but not without cost. Rodents gnawing on tubing, spouts, and fittings may cause damage in excess of $300,000 annually in Vermont, the largest maple producing state. Red squirrels (Tamiasciurus hudsonicu3), gray squirrels (Sciurus carolinensis), and chipmunks (Tamias striatus) appear to be responsible for the majority of damage. Other species including flying squirrels (Glaucomvs sabrinus) , white-footed mice (Peromvscus leucopus), porcupines (Erethizon dorsatum), and woodpeckers (Picidae spp.) may also cause substantial damage. Past attempts to control damage with zinc phosphide treated grain, shooting, and trapping have been costly, labor intensive, and generally unsuccessful. Control techniques including habitat manipulation, repellents and exclusion with electric polywire are being field tested. Mast crops are being monitored in an attempt to predict changes in rodent populations, and tooth mark patterns on tubing are being studied so that the 1/USDA/APHIS/ADC, Wildlife Biologist 87 State Street, Room 222, PO Box 1436 Montpelier, VT 05601-1436 J/USDA/APHIS/ADC, State Director NH/VT 22 Bridge Street, Suite 302, PO Box 2398, Concord, NH 03302-2398 species responsible for the damage can be properly identified. INTRODUCTION Vermont is the largest maple producing state in the U.S. with over 2,500 sugar makers that collect and process over 20 million gallons of sap per year. Average annual syrup production is over 500,000 gallons with an estimated value of $30 million when support industries (equipment, packaging, etc.) and hired labor are included. In recent years maple syrup producers have turned to new technology to increase yields and stay competitive. The days of wood-fired evaporators and horse-drawn sleighs carrying gathering tanks from the woods to the sugar house are yielding to oil-fired evaporators, reverse osmosis machines, ultraviolet sap treatment, and plastic tubing gathering systems. These tubing systems generally consist of 0.08 cm dia. (5/16 in.) plastic droplines connected to a spout that may be driven into the tree. A 0.08 cm. dia. lateral line connects 20 40 droplines before emptying into a 1.9 10.2 cm dia. (0.75 4 inch) mainline. Mainlines collect sap from several lateral lines and ultimately empty into collection tanks that may be located in or near the sugar house where sap is processed. Most large producers leave their tubing in place throughout the year because of labor costs associated with retrieving tubing and subsequently