The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform
Rachael S Moulton - One of the best experts on this subject based on the ideXlab platform.
-
retention time of Chlorophacinone in black tailed prairie dogs informs secondary hazards from a prairie dog rodenticide bait
Pest Management Science, 2016Co-Authors: Gary W Witmer, Nathan P Snow, Rachael S MoultonAbstract:BACKGROUND Secondary toxicity in mammals and birds that consume animals containing residues of anticoagulant rodenticides represents a persistent conflict between conservation, agriculture and environmental contamination. Chlorophacinone residues in black-tailed prairie dogs (Cynomys ludovicianus) represent a secondary exposure hazard to predatory and scavenging avian and mammalian species in the Central Plains of the United States, especially considering efforts to re-establish black-footed ferrets (Mustela nigripes). Rozol® Prairie Dog Bait (Chlorophacinone 0.005%) is registered to control black-tailed prairie dogs in ten states throughout the midwestern and western United States. RESULTS We fed Rozol Prairie Dog Bait to captive black-tailed prairie dogs for 2 days and analyzed their livers and whole bodies (without livers) for Chlorophacinone residue on days 3, 5, 7, 9, 11, 14, 18 and 27 post-exposure. We found the greatest levels of residues in livers ( = 5.499 mg kg−1) and whole bodies ( = 1.281 mg kg−1) on day 3. Residues in both tissues declined rapidly over time, with estimated half-lives of approximately 6 days post-exposure. However, a risk assessment of secondary toxicity to non-target mammals indicated acute risks for mammalian species up to 27 days post-exposure and negligible risks for birds. CONCLUSION The results suggest that the greatest risk of secondary toxicity occurs ≤14 days post-application of Rozol Prairie Dog Bait and declines thereafter. This corresponds to the time when Chlorophacinone residues are high, and prairie dogs exhibit signs of intoxication and are perhaps most susceptible to predation and scavenging. These results confirm that Rozol Prairie Dog Bait should not be used in areas where black-footed ferrets or other sensitive species occur. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.
-
the effects of vitamin k1 rich plant foods on the efficacy of the anticoagulant rodenticides Chlorophacinone and diphacinone used against montane voles microtus montanus
International Journal of Pest Management, 2013Co-Authors: Gary W Witmer, Nathan P Snow, Rachael S MoultonAbstract:Voles can cause significant losses to agriculture and wood fibre production. California growers typically rely on baits containing Chlorophacinone and diphacinone to reduce vole population densities, but the efficacy of those rodenticides has been decreasing. One hypothesis suggests that voles are consuming high levels of an antidote (vitamin K1) to the anticoagulants, contained within green leafy plants. We tested that hypothesis by first feeding Montane Voles (Microtus montanus) diets that were high in vitamin K1, and then providing the animals with either: (1) Chlorophacinone-containing bait, (2) diphacinone-containing bait, or (3) a control diet. We found that the Chlorophacinone-containing bait remained efficacious (100% mortality), whereas the diphacinone-containing bait had a much lower efficacy (60% mortality). When only the diphacinone-containing bait was presented, the efficacy was somewhat better (80%). We infer that a diet rich in vitamin K1 did not negate the effects of the Chlorophacinone fo...
Clifford P. Rice - One of the best experts on this subject based on the ideXlab platform.
-
Evidence of Songbird Intoxication From Rozol® Application at a Black-Tailed Prairie Dog Colony
Journal of Fish and Wildlife Management, 2013Co-Authors: Nimish B. Vyas, Craig S. Hulse, Carol U. Meteyer, Clifford P. RiceAbstract:Abstract Concerns about avian poisonings from anticoagulant rodenticides have traditionally focused on secondary poisoning of raptors exposed by feeding on contaminated mammalian prey. However, ground foraging songbirds can be directly poisoned from operational applications of the anticoagulant rodenticide Rozol® (0.005% Chlorophacinone, active ingredient) applied as a grain bait, at black-tailed prairie dog Cynomys ludovicianus colonies. A dead western meadowlark Sturnella neglecta recovered from the study prairie dog colony displayed hemorrhaging in brain and pectoral muscle tissue, and it contained Chlorophacinone residue concentrations of 0.59 and 0.49 µg/g (wet weight) in the liver and intestinal contents, respectively. Chlorophacinone residues from two Rozol-colored songbird droppings found at the study colony were 0.09 and 0.46 µg/g (wet weight). The timing of the meadowlark mortality and the occurrence of discolored droppings show that songbird exposure and poisoning can occur weeks after a Rozol ...
-
Chlorophacinone residues in mammalian prey at a black tailed prairie dog colony
Environmental Toxicology and Chemistry, 2012Co-Authors: Nimish B. Vyas, Craig S. Hulse, Clifford P. RiceAbstract:Black-tailed prairie dogs (BTPDs), Cynomys ludovicianus, are an important prey for raptors; therefore, the use of the rodenticide Rozol (0.005% Chlorophacinone active ingredient) to control BTPDs raises concern for secondary poisonings resulting from the consumption of contaminated prey by raptors. In the present study, the authors observed Rozol exposure and adverse effects to mammalian prey on 11 of 12 search days of the study. Mammalian hepatic Chlorophacinone residues ranged from 0.44 to 7.56 µg/g. Poisoned prey availability was greater than previously reported. Environ. Toxicol. Chem. 2012; 31: 2513–2516. © 2012 SETAC
-
Chlorophacinone residues in mammalian prey at a black‐tailed prairie dog colony
Environmental Toxicology and Chemistry, 2012Co-Authors: Nimish B. Vyas, Craig S. Hulse, Clifford P. RiceAbstract:Black-tailed prairie dogs (BTPDs), Cynomys ludovicianus, are an important prey for raptors; therefore, the use of the rodenticide Rozol (0.005% Chlorophacinone active ingredient) to control BTPDs raises concern for secondary poisonings resulting from the consumption of contaminated prey by raptors. In the present study, the authors observed Rozol exposure and adverse effects to mammalian prey on 11 of 12 search days of the study. Mammalian hepatic Chlorophacinone residues ranged from 0.44 to 7.56 µg/g. Poisoned prey availability was greater than previously reported. Environ. Toxicol. Chem. 2012; 31: 2513–2516. © 2012 SETAC
John J Johnston - One of the best experts on this subject based on the ideXlab platform.
-
weatherability of a steam rolled oat groat Chlorophacinone ground squirrel bait under field and laboratory conditions
International Biodeterioration & Biodegradation, 2000Co-Authors: Craig A Ramey, Thomas M Primus, Doreen L Griffin, John J JohnstonAbstract:Abstract Investigations of the weatherability of spot-baiting for ground squirrel control in northern CA field studies were conducted with a registered bait consisting of 0.01% Chlorophacinone (an anticoagulant rodenticide) on steam-rolled oat groats. For reference purposes, a laboratory test was later conducted in an environmental chamber simulating some of the observed weather conditions. Three weathering plots were established in alfalfa for field tests. Each was baited with rodenticide fortified bait that was handled the same as for a simultaneous control project. Test areas were protected with wire mesh to prevent bait consumption by birds and mammals. Bait samples were collected daily over 7 days, then frozen, and shipped for analysis. Test No. 1 conducted under wet conditions showed a 71% loss of Chlorophacinone after 1 week. Test No. 2 demonstrated a 57% loss of Chlorophacinone under drier conditions. Test No. 3, a 24 h test under very wet conditions within the alfalfa field irrigated by overhead sprinklers, had a 92% loss of Chlorophacinone. Laboratory studies using controlled environmental conditions: light (16 h light:8 h dark), with a mean relative humidity of 98%, and a range of temperature 11.1–27.8°C (52–82°F) showed ≈50% loss of the Chlorophacinone. The magnitude was less (37% at 7 days) in the environmental chamber when corrected for water weight gain.
-
reversed phase ion pair liquid chromatographic determination of Chlorophacinone and diphacinone in steam rolled oat baits and steam rolled oat wax baits
Journal of AOAC International, 1998Co-Authors: Thomas M Primus, Doreen L Griffin, Stephanite A Volz, John J JohnstonAbstract:: A reversed-phase ion-pair liquid chromatographic (LC) method was developed for analysis of steam-rolled oat (SRO) baits fortified with either Chlorophacinone or diphacinone. Baits were prepared with and without paraffin wax. Chlorophacinone or diphacinone was extracted from wax-free SRO baits with 5 mM tetrabutylammonium phosphate methanolic ion-pairing solution. Wax baits were initially extracted with petroleum ether and then cleaned up by liquid extraction into methanolic ion-pairing solution containing 20% water. SRO extracts were analyzed with reversed-phase ion-pair LC. Chlorophacinone and diphacinone were quantified by UV absorption at 325 nm. Recoveries from SRO fortified with Chlorophacinone at 25 and 150 micrograms/g were 90.7 and 90.8%, respectively, whereas for diphacinone at the same levels, recoveries were 93.5 and 92.3%, respectively. Recoveries from wax baits fortified at 25 and 75 micrograms/g Chlorophacinone were 98.5 and 100%, respectively, whereas for diphacinone at the same levels, recoveries were 93.6 and 98.0%, respectively. Method limits of detection for Chlorophacinone and diphacinone in SRO baits were estimated to be 1.0 and 0.76 micrograms/g, respectively. Method limits of detection for Chlorophacinone and diphacinone in wax baits were estimated to be 4.2 and 2.8 micrograms/g, respectively.
-
solid phase extraction and reversed phase ion pair high performance liquid chromatographic determination of Chlorophacinone and diphacinone residues in range grass
Journal of Chromatographic Science, 1996Co-Authors: Thomas M Primus, David A Goldade, Eric E Petty, John J JohnstonAbstract:A reversed-phase ion-pair liquid chromatographic method is developed for the analysis of Chlorophacinone and diphacinone in range grass. Chlorophacinone and diphacinone are extracted from range grass with chloroform, and the extracts are subjected to an aminopropyl solid-phase extraction procedure, concentrated, and analyzed by reversed-phase ion-pair high-performance liquid chromatography. Chlorophacinone and diphacinone are detected by ultraviolet absorption at 285 nm. The average recoveries from range grass fortified at 0.10,1.0, and 10.0 µg/g Chlorophacinone and diphacinone are 94% ± 3 and 97% ± 6. The limit of detection for Chlorophacinone and diphacinone in range grass is estimated to be 0.015 µg/g and 0.013 µg/g, respectively.
Nimish B. Vyas - One of the best experts on this subject based on the ideXlab platform.
-
Evidence of Songbird Intoxication From Rozol® Application at a Black-Tailed Prairie Dog Colony
Journal of Fish and Wildlife Management, 2013Co-Authors: Nimish B. Vyas, Craig S. Hulse, Carol U. Meteyer, Clifford P. RiceAbstract:Abstract Concerns about avian poisonings from anticoagulant rodenticides have traditionally focused on secondary poisoning of raptors exposed by feeding on contaminated mammalian prey. However, ground foraging songbirds can be directly poisoned from operational applications of the anticoagulant rodenticide Rozol® (0.005% Chlorophacinone, active ingredient) applied as a grain bait, at black-tailed prairie dog Cynomys ludovicianus colonies. A dead western meadowlark Sturnella neglecta recovered from the study prairie dog colony displayed hemorrhaging in brain and pectoral muscle tissue, and it contained Chlorophacinone residue concentrations of 0.59 and 0.49 µg/g (wet weight) in the liver and intestinal contents, respectively. Chlorophacinone residues from two Rozol-colored songbird droppings found at the study colony were 0.09 and 0.46 µg/g (wet weight). The timing of the meadowlark mortality and the occurrence of discolored droppings show that songbird exposure and poisoning can occur weeks after a Rozol ...
-
Chlorophacinone residues in mammalian prey at a black tailed prairie dog colony
Environmental Toxicology and Chemistry, 2012Co-Authors: Nimish B. Vyas, Craig S. Hulse, Clifford P. RiceAbstract:Black-tailed prairie dogs (BTPDs), Cynomys ludovicianus, are an important prey for raptors; therefore, the use of the rodenticide Rozol (0.005% Chlorophacinone active ingredient) to control BTPDs raises concern for secondary poisonings resulting from the consumption of contaminated prey by raptors. In the present study, the authors observed Rozol exposure and adverse effects to mammalian prey on 11 of 12 search days of the study. Mammalian hepatic Chlorophacinone residues ranged from 0.44 to 7.56 µg/g. Poisoned prey availability was greater than previously reported. Environ. Toxicol. Chem. 2012; 31: 2513–2516. © 2012 SETAC
-
Chlorophacinone residues in mammalian prey at a black‐tailed prairie dog colony
Environmental Toxicology and Chemistry, 2012Co-Authors: Nimish B. Vyas, Craig S. Hulse, Clifford P. RiceAbstract:Black-tailed prairie dogs (BTPDs), Cynomys ludovicianus, are an important prey for raptors; therefore, the use of the rodenticide Rozol (0.005% Chlorophacinone active ingredient) to control BTPDs raises concern for secondary poisonings resulting from the consumption of contaminated prey by raptors. In the present study, the authors observed Rozol exposure and adverse effects to mammalian prey on 11 of 12 search days of the study. Mammalian hepatic Chlorophacinone residues ranged from 0.44 to 7.56 µg/g. Poisoned prey availability was greater than previously reported. Environ. Toxicol. Chem. 2012; 31: 2513–2516. © 2012 SETAC
Thomas M Primus - One of the best experts on this subject based on the ideXlab platform.
-
The Use of Liver Microsome In -Vitro Methods to Study Toxicant Metabolism and Predict Species Efficacy
Proceedings of the Vertebrate Pest Conference, 2020Co-Authors: Katherine E. Horak, Chad R. Wermager, Thomas M PrimusAbstract:Liver microsomes are used extensively in human pharmaceutical development to study the metabolism of co mpounds of interest; however, they are rarely part of the development of toxicants for the control of wildlife. Liver microsome samples from wildlife of interest would likely be harvested in the field without access to laboratory perfusion equipment. Therefore, the metabolic activity of microsomes from perfused and non*perfused livers was compared. There was no significant difference in diphacinone metabolism by liver microsomes from both perfused and non*perfused Wistar rat livers, although Chlorophacinone metabolism was significantly different. There are often significant differences in metabolism between species that can be utilized to increase toxicant specificity. In this study bobwhite quail liver microsomes metabolized more diphacinone and Chlorophacinone than both Wistar and brown rats. This information can be used during toxicant development to help determine the most sensitive species to toxicants of interest. Additionally, the effect of incubation time on toxicant metabolism was examined to determine optimal experimental conditions. The data from these experiments support the use of liver microsomes as a tool to be used during toxicant development to provide information that can be incorporated into whole animal studies.
-
assessing the efficacy of Chlorophacinone for mountain beaver aplodontia rufa control
Proceedings of the Vertebrate Pest Conference, 2004Co-Authors: Wendy M. Arjo, Thomas M Primus, Dale L. Nolte, Dennis J KohlerAbstract:Author(s): Arjo, Wendy M.; Nolte, Dale L.; Primus, Thomas M.; Kohler, Dennis J. | Abstract: The mountain beaver is a fossorial rodent species endemic to the Pacific Northwest and portions of California. This herbivore is managed as a pest species because of the impact it has on newly planted Douglas-fir seedlings. Currently, managers are limited to trapping for population control; however, in Washington trapping has been further curtailed by anti-trapping legislation. Presently there are no registered underground toxicants for mountain beaver control. We have documented the efficacy of Chlorophacinone, presented in daily doses, as a possible alternative for mountain beaver control. Daily baiting would be unreasonable and costly alternative for timber managers, so we conducted a series of tests to determine if a single or double baiting was efficacious. In addition, we tested the caching behavior of the mountain beaver when offered bags of oats. This behavior may help reduce impacts to non-target species as well reduce environmental exposure and degradation. Mountain beaver readily cached bags of Chlorophacinone within their artificial burrows, and efficacy of a one-time and two-time dose was 100%. We determined that even with the highest Chlorophacinone residuals (0.354 ppm) that the risk quotient for mink and red-tailed hawk was exactly at the level of concern that EPA recognizes for endangered and threatened species.
-
weatherability of a steam rolled oat groat Chlorophacinone ground squirrel bait under field and laboratory conditions
International Biodeterioration & Biodegradation, 2000Co-Authors: Craig A Ramey, Thomas M Primus, Doreen L Griffin, John J JohnstonAbstract:Abstract Investigations of the weatherability of spot-baiting for ground squirrel control in northern CA field studies were conducted with a registered bait consisting of 0.01% Chlorophacinone (an anticoagulant rodenticide) on steam-rolled oat groats. For reference purposes, a laboratory test was later conducted in an environmental chamber simulating some of the observed weather conditions. Three weathering plots were established in alfalfa for field tests. Each was baited with rodenticide fortified bait that was handled the same as for a simultaneous control project. Test areas were protected with wire mesh to prevent bait consumption by birds and mammals. Bait samples were collected daily over 7 days, then frozen, and shipped for analysis. Test No. 1 conducted under wet conditions showed a 71% loss of Chlorophacinone after 1 week. Test No. 2 demonstrated a 57% loss of Chlorophacinone under drier conditions. Test No. 3, a 24 h test under very wet conditions within the alfalfa field irrigated by overhead sprinklers, had a 92% loss of Chlorophacinone. Laboratory studies using controlled environmental conditions: light (16 h light:8 h dark), with a mean relative humidity of 98%, and a range of temperature 11.1–27.8°C (52–82°F) showed ≈50% loss of the Chlorophacinone. The magnitude was less (37% at 7 days) in the environmental chamber when corrected for water weight gain.
-
reversed phase ion pair liquid chromatographic determination of Chlorophacinone and diphacinone in steam rolled oat baits and steam rolled oat wax baits
Journal of AOAC International, 1998Co-Authors: Thomas M Primus, Doreen L Griffin, Stephanite A Volz, John J JohnstonAbstract:: A reversed-phase ion-pair liquid chromatographic (LC) method was developed for analysis of steam-rolled oat (SRO) baits fortified with either Chlorophacinone or diphacinone. Baits were prepared with and without paraffin wax. Chlorophacinone or diphacinone was extracted from wax-free SRO baits with 5 mM tetrabutylammonium phosphate methanolic ion-pairing solution. Wax baits were initially extracted with petroleum ether and then cleaned up by liquid extraction into methanolic ion-pairing solution containing 20% water. SRO extracts were analyzed with reversed-phase ion-pair LC. Chlorophacinone and diphacinone were quantified by UV absorption at 325 nm. Recoveries from SRO fortified with Chlorophacinone at 25 and 150 micrograms/g were 90.7 and 90.8%, respectively, whereas for diphacinone at the same levels, recoveries were 93.5 and 92.3%, respectively. Recoveries from wax baits fortified at 25 and 75 micrograms/g Chlorophacinone were 98.5 and 100%, respectively, whereas for diphacinone at the same levels, recoveries were 93.6 and 98.0%, respectively. Method limits of detection for Chlorophacinone and diphacinone in SRO baits were estimated to be 1.0 and 0.76 micrograms/g, respectively. Method limits of detection for Chlorophacinone and diphacinone in wax baits were estimated to be 4.2 and 2.8 micrograms/g, respectively.
-
solid phase extraction and reversed phase ion pair high performance liquid chromatographic determination of Chlorophacinone and diphacinone residues in range grass
Journal of Chromatographic Science, 1996Co-Authors: Thomas M Primus, David A Goldade, Eric E Petty, John J JohnstonAbstract:A reversed-phase ion-pair liquid chromatographic method is developed for the analysis of Chlorophacinone and diphacinone in range grass. Chlorophacinone and diphacinone are extracted from range grass with chloroform, and the extracts are subjected to an aminopropyl solid-phase extraction procedure, concentrated, and analyzed by reversed-phase ion-pair high-performance liquid chromatography. Chlorophacinone and diphacinone are detected by ultraviolet absorption at 285 nm. The average recoveries from range grass fortified at 0.10,1.0, and 10.0 µg/g Chlorophacinone and diphacinone are 94% ± 3 and 97% ± 6. The limit of detection for Chlorophacinone and diphacinone in range grass is estimated to be 0.015 µg/g and 0.013 µg/g, respectively.