Relationship Between Seasonal Changes in Forage Quality and Feeding Patterns in Meadow Voles (Microtus pennsylvanicus)

Forage analyses revealed that mowed orchards provide a relatively high quality forage to meadow voles (Microtus pennsylvanicus), especially in the fall. Mowed forage was characterized by significantly higher protein and moisture content and significantly lower acid and neutral detergent fibre and lignin than forage from an abandoned orchard. Energy and fat were not significantly affected by mowing. However, vole numbers declined markedly in mowed regions in comparison to undisturbed areas. Voles preferred to inhabit areas with dense cover even though vegetative dieback had occurred. Voles did not exhibit any distinct preference for either cracked corn (rodenticide carrier agent) or available forage at any time during the study. Voles did not change rates of forage consumption over the 6-month study. We conclude that mowing will not reduce acceptability of cracked corn and that removal of dense ground cover from the orchard would be one of the most effective and economical ways to reduce numbers of voles and minimize tree damage

A CURRENT ASSESSMENT OF VOLE DAMAGE AND NUMBERS AND OF METHODS USED TO CONTROL VOLES IN ONTARIO APPLE ORCHARDS

A province-wide evaluation of the amount, distribution, source and control of damage to Ontario apple trees was initiated. Data we re obtained from 280 responses to a questionnaire distributed to growers across Ontario, and from trap censuses in three widely separated areas. Meadow voles (Microtus pennsylvanicus) damaged or destroyed 8,423 trees in our questionnaire sample and other mammals damaged another 10,307 trees. No relationship was found between application of rodenticide and levels of damage, but rodenticide-treated baits sharply reduced numbers of voles on our trap plots. Orchards with high levels of damage were on average only one-third as large as the average orchard in our total sample. All damage by voles appeared to be caused by meadow voles and no pine voles (M. pinetorum) were found. Numbers of voles varied greatly among our three study areas. Future work will concentrate on factors causing high levels of damage and on the relationship between dispersal of voles and the effects of rodenticide treatment

A CURRENT ASSESSMENT OF VOLE DAMAGE AND NUMBERS AND OF METHODS USED TO CONTROL VOLES IN ONTARIO APPLE ORCHARDS

A province-wide evaluation of the amount, distribution, source and control of damage to Ontario apple trees was initiated. Data we re obtained from 280 responses to a questionnaire distributed to growers across Ontario, and from trap censuses in three widely separated areas. Meadow voles (Microtus pennsylvanicus) damaged or destroyed 8,423 trees in our questionnaire sample and other mammals damaged another 10,307 trees. No relationship was found between application of rodenticide and levels of damage, but rodenticide-treated baits sharply reduced numbers of voles on our trap plots. Orchards with high levels of damage were on average only one-third as large as the average orchard in our total sample. All damage by voles appeared to be caused by meadow voles and no pine voles (M. pinetorum) were found. Numbers of voles varied greatly among our three study areas. Future work will concentrate on factors causing high levels of damage and on the relationship between dispersal of voles and the effects of rodenticide treatment

Control of Damage by Mammals in Ontario Orchards

Each year, mammalian wildlife causes extensive and costly damage to fruit tree growers throughout Ontario. In 1981, in response to the concern among fruit growers over high levels of this damage, the Ontario Apple Marketing Commission and the Ontario Ministry of Agriculture and Food requested that we initiate a long-term study of this problem. However, the desire to improve available control practices was impeded by a general lack of know ledge of the scope of mammalian pest problems in Ontario. For example, the extent and degree of damage in relation to seasonal and regional differences, pest population levels and management practices was unknown. Accordingly, our research program has four basic objectives: first, to assess level of tree injury caused by mammalian pests and to deter-mine the costs of this damage and of methods currently used to control the pest species; second, to identify the species causing damage; third, to identify biological indicators that could be used by growers to predict periods of potential high damage; fourth, to develop and recommend a cost-effective, long-range program to monitor and control pest species

Effects of Glyphosate and its Formulation, Roundup, on Reproduction in Zebrafish (Danio rerio)

This is an open access article that is freely available in ORE or from the publisher's web site. Please cite the published version.Copyright © 2014 American Chemical SocietyRoundup and its active ingredient glyphosate are among the most widely used herbicides worldwide and may contaminate surface waters. Research suggests both Roundup and glyphosate induce oxidative stress in fish and may also cause reproductive toxicity in mammalian systems. We aimed to investigate the reproductive effects of Roundup and glyphosate in fish and the potential associated mechanisms of toxicity. To do this, we conducted a 21-day exposure of breeding zebrafish (Danio rerio) to 0.01, 0.5, and 10 mg/L (glyphosate acid equivalent) Roundup and 10 mg/L glyphosate. 10 mg/L glyphosate reduced egg production but not fertilization rate in breeding colonies. Both 10 mg/L Roundup and glyphosate increased early stage embryo mortalities and premature hatching. However, exposure during embryogenesis alone did not increase embryo mortality, suggesting that this effect was caused primarily by exposure during gametogenesis. Transcript profiling of the gonads revealed 10 mg/L Roundup and glyphosate induced changes in the expression of cyp19a1 and esr1 in the ovary and hsd3b2, cat, and sod1 in the testis. Our results demonstrate that these chemicals cause reproductive toxicity in zebrafish, although only at high concentrations unlikely to occur in the environment, and likely mechanisms of toxicity include disruption of the steroidogenic biosynthesis pathway and oxidative stress.Natural Environment Research Counci

ECONOMICS AND CONTROL OF DAMAGE CAUSED BY LOW-DENSITY POPULATIONS OF MEADOW VOLES IN ONTARIO APPLE ORCHARDS

Live trapping and questionnaires were used to evaluate amount, distribution, and costs of control of damage to Ontario apple trees by meadow voles (Microtus enns lvanicus) in 1981-82. In a sample of 180 orchards, 5802 (0.77%) trees were damaged or killed by voles. Orchards with high levels of damage (\u3e 2.5%) were smaller than the average orchard in our sample. Application of rodenticides showed no relationship to levels of damage, but was effective in short-term population reduction. Growers spent an average of $17/ha on rodenticides and$38/ha on herbicides, and they estimated that voles destroyed 2% of their crop each year. About 55% of our sample of growers stated that damage by voles was more significant than that caused by insects or other pests. In the 1981-82 season, vole numbers were lower than in 1980-81, and reported levels of damage were also lower. These differences are discussed

RELATIONSHIP BETWEEN SEASONAL CHANGES IN FORAGE QUALITY AND FEEDING PATTERNS IN MEADOW VOLES (\u3ci\u3eMICROTUS PENNSYLVANICUS\u3c/i\u3e)

Forage analyses revealed that mowed orchards provide a relatively high quality forage to meadow voles (Microtus pennsylvanicus), especially in the fall. Mowed forage was characterized by significantly higher protein and moisture content and significantly lower acid and neutral detergent fibre and lignin than forage from an abandoned orchard. Energy and fat were not significantly affected by mowing.. However, vole numbers declined markedly in mowed regions in comparison to undisturbed areas. Voles preferred to inhabit areas with dense cover even though vegetative dieback had occurred. Voles did not exhibit any distinct preference for either cracked corn (rodenticide carrier agent) or available forage at any time during the study. Voles did not change rates of forage consumption over the 6-month study. We conclude that mowing will not reduce acceptability of cracked corn and that removal of dense ground cover from the orchard would be one of the most effective and economical ways to reduce numbers of voles and minimize tree damage