Search

This paper focuses on managing wildlife damage in forest environments, with emphasis on the use of vertebrate pesticides in the western United States. Types of forest damage caused by vertebrates fall into the categories of seed destruction, foliage clipping and browsing, and root and bark injuries. Consumption of natural seedfall or following direct-seeding applications for reforestation varies with tree species as well as with vertebrate seed predators, which include both rodents and birds. With Douglas-fir, deer mice (Peromyscus spp.) are cause the greatest losses. For Ponderosa pine, deer mice, chipmunks, and ground squirrels are primarily responsible for seed loss. Seeding in black walnut is primarily impacted by gray squirrels and the eastern fox squirrel. Success with rodenticide treatments in advance of seed applications were only effective for short periods, as rodent populations rebounded quickly. Current efforts are relying on various seed coatings that provide greater efficacy. Clipping by small rodents is a particular problem with newly emerged seedlings; existing seedlings are also damaged by snowshoe hares and mountain beaver in the Pacific Coast states. Contact repellents have been effective but may need to be re-applied periodically. Browsing damage to existing conifer stands is caused primarily by deer and elk, and there is no general solution for this problem. Root injury to seedling and small saplings is most frequently caused by pocket gophers. A variety of animals may cause bark injuries: meadow mice (Microtus spp.) can seriously damage seedlings, while bark damage to both young and also mature trees can be caused by porcupine, woodrats, rabbits, squirrels, and pocket gophers. Bear damage to bark is usually seen on mature trees. Seed treatment formulations using endrin as the active ingredient are described, as are a foliar repellent treatment using TMTD, and the manufacture and use of salt blocks containing strychnine for porcupine control. Pe

Biology, damage, management, and control of rabbits (genus Sylvilagus) and hares (genus Lepus) in California are described. This paper places emphasis on control of the common jackrabbit, Lepus californicus, as it is the most significant of the rabbit and hare species in California and the western states in terms of damage and the need for control. Exclusion methods are discussed, including rabbit-proof fences as well as individual plant and tree protectors. A summary of repellents used against hares and rabbits is provided, as well as precautions for their use. They typically provide only temporary effectiveness. A recipe for a strychnine-based poison wash for trees, which has found to be of use as a repellent, is provided. Use of toxic baits to control rabbits and hares is described, with appropriate precautions. Bait formulation and application are discussed in some detail, with use of strychnine as the active ingredient. Recipes are provided for formulating both prebait and toxic baits; the primary ingredient can be barley, oats, root vegetables (carrot, sweet potato, or parsnip), fruit (green pears or cull apples), dry alfalfa leaves, or grain heads using barley or milo.

This paper focuses on managing wildlife damage in forest environments, with emphasis on the use of vertebrate pesticides in the western United States. Types of forest damage caused by vertebrates fall into the categories of seed destruction, foliage clipping and browsing, and root and bark injuries. Consumption of natural seedfall or following direct-seeding applications for reforestation varies with tree species as well as with vertebrate seed predators, which include both rodents and birds. With Douglas-fir, deer mice (Peromyscus spp.) are cause the greatest losses. For Ponderosa pine, deer mice, chipmunks, and ground squirrels are primarily responsible for seed loss. Seeding in black walnut is primarily impacted by gray squirrels and the eastern fox squirrel. Success with rodenticide treatments in advance of seed applications were only effective for short periods, as rodent populations rebounded quickly. Current efforts are relying on various seed coatings that provide greater efficacy. Clipping by small rodents is a particular problem with newly emerged seedlings; existing seedlings are also damaged by snowshoe hares and mountain beaver in the Pacific Coast states. Contact repellents have been effective but may need to be re-applied periodically. Browsing damage to existing conifer stands is caused primarily by deer and elk, and there is no general solution for this problem. Root injury to seedling and small saplings is most frequently caused by pocket gophers. A variety of animals may cause bark injuries: meadow mice (Microtus spp.) can seriously damage seedlings, while bark damage to both young and also mature trees can be caused by porcupine, woodrats, rabbits, squirrels, and pocket gophers. Bear damage to bark is usually seen on mature trees. Seed treatment formulations using endrin as the active ingredient are described, as are a foliar repellent treatment using TMTD, and the manufacture and use of salt blocks containing strychnine for porcupine control. Pe

Biology, damage, management, and control of rabbits (genus Sylvilagus) and hares (genus Lepus) in California are described. This paper places emphasis on control of the common jackrabbit, Lepus californicus, as it is the most significant of the rabbit and hare species in California and the western states in terms of damage and the need for control. Exclusion methods are discussed, including rabbit-proof fences as well as individual plant and tree protectors. A summary of repellents used against hares and rabbits is provided, as well as precautions for their use. They typically provide only temporary effectiveness. A recipe for a strychnine-based poison wash for trees, which has found to be of use as a repellent, is provided. Use of toxic baits to control rabbits and hares is described, with appropriate precautions. Bait formulation and application are discussed in some detail, with use of strychnine as the active ingredient. Recipes are provided for formulating both prebait and toxic baits; the primary ingredient can be barley, oats, root vegetables (carrot, sweet potato, or parsnip), fruit (green pears or cull apples), dry alfalfa leaves, or grain heads using barley or milo.