Wildlife Damage Management, Internet Center for


Date of this Version

March 1981


Published in Proceedings of the Fifth Eastern Pine and Meadow Vole Symposium, Gettysburg, PA, March 4–5, 1981, Ross E. Byers, editor. Copyright © 1981 Young.


The toxicants were placed in an apple orchard consisting of 'Rome' and 'Golden Delicious' trees planted in 1954 at a distance of 20 by 20 feet and thinned to 20 by 40 feet in 1972. Pine voles have been for several years the dominant vole infesting the orchard and have caused an 8% tree loss. Vole activity sites were selected at 30 trees per treatment. Bait applications of brodifacoum (Volak) and chlorophacinone (Rozol) were made by hand placement under roofing pads at one activity site per tree. A treatment was included using the "Mouse-ateria", as the bait station for comparison with the roofing pad bait station. An attempt was made to place the open end of the "Mouse-ateria" at one active vole site per tree. One packet of the Volak bait was placed in each "Mouse-ateria". Pre-baiting vole activity ratings were made December 5-6, 1979. Amount of apple eaten was used as the criterion indicator for activity. Activity rating was based upon the scale of 0 to 10, where 0 = no portion of apple eaten, 3 = less than 50% of flesh eaten, 5 = 50 to 80% of flesh eaten, 8 = 100% of flesh eaten, and 10 = flesh and skin completely consumed. Post-baiting observations of bait consumption was made December 17, 1979. Post-bait activity rating, using apple as the indicator, was made June 3, 1980.