Monitoring and assessment of Swainson's Hawks in Argentina following restrictions on monocrotophos use, 199697 (original) (raw)
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Monocrotophos-induced mass mortality of Swainson's Hawks in Argentina, 199596
Ecotoxicology, 1999
. Ž . Abstract. Swainson's hawks Buteo swainsoni were observed in the grasslands pampas of Argentina during the austral summer of 1995᎐96. Widespread agrochemical use to control insects had a profound effect on flocks of hawks foraging on grasshoppers and caterpillars throughout the pampas. We describe 19 mortality incidents and an estimated 5,095 dead hawks. Forensic analysis indicated that the organophosphate insecticide monocrotophos was responsible for the deaths at six separate sites, account-Ž . ing for over 4,000 of the mortalities. Brain cholinesterase was lethally inhibited ) 95% and monocro-Ž . tophos residues n s 31r45, mean s 0.20 ppm, range 0.05᎐1.08 ppm were found in the contents of the gastrointestinal tract. No other insecticide residues were found. Sample analyses, combined with interviews with farmers, indicated that monocrotophos was responsible for deaths at 17 of 19 mortality incidents.
Organophosphorus Insecticide Exposure In Hawks Inhabiting Orchards During Winter Dormant-Spraying
Bulletin of environmental …, 1989
The Sacramento and San Joaquin Valleys of California contain over 400,000 acres of almond orchards sprayed during the winter dormant season with a mixture of oil and mainly one of three organophosphorus (OP) insecticides; parathion; O-O-diethyl O-pnitrophenyl phosphorothioate, Diazinon; O,O-diethyl O-(2isopropyl-6-methyl-4-pyrimidyl) phosphorothioate, or methidathion; O,O-dimethyl Rhosphorodithioate, S-ester with 4-(mercaptomethyl)-2-methoxy-L-1,3,4-thiadiazolin-5-one) (Van Steenwyk, et al., 1983). Reports of red-tailed Hawk (Buteo jamaicensis, RT) losses during the dormant season have been made to the California Department of Fish and Game (CDFG, Ed Littrell, pers. comm.) by wildlife rehabilitation groups in heavy almond production areas in California's Central Valley. Hawks were brought to their centers with signs of OP exposure that responded to treatment with atropine, an antidote to OP poisoning.
The Condor, 2010
Monitoring programs indicate that numerous shorebird populations are subject to ongoing declines. The U.S. Shorebird Conservation Plan lists twenty-seven shorebird species as species of high concern and seven as highly imperiled, including the Buff-breasted Sandpiper (Tryngites subruficollis). One hypothesis for ongoing population declines is exposure to toxic chemicals and pollutants. The purpose of this project was to characterize plasma cholinesterases (ChEs) of migratory shorebirds and address potential exposure to organophosphorus (OP) and carbamate (CB) pesticides. Consumption or contact with these pesticides can cause mortality and a variety of sub-lethal effects. Buff-breasted Sandpipers and other upland shorebirds are particularly likely to encounter agrochemicals due to their habitat use at the non-breeding grounds. I sampled migratory shorebirds over three seasons, during north-and southbound migration in 2006 and 2007 in Texas, Kansas, and Nebraska and during the non-breeding season in 2007 in Argentina, Uruguay, and Paraguay. I collected blood samples and footwashings from reference sites, where OP and CB pesticides were not used, and agricultural sites, where these two insecticides were recommended for control of crop pests. I assessed several variables known to affect plasma ChE activity including body size, date of capture, time of capture, condition, sex, and region. Small-bodied species had higher levels of ChE activity in plasma than large-bodied species. Plasma ChE activities varied with date of capture in 3 of 5 species sampled in North America. Sex differences were significant in 1 of 4 species tested. Plasma acetylcholinesterase (AChE) activity was higher among White-rumped Sandpipers sampled in North America but there was no difference between regions among Buff-breasted Sandpipers.
Simulating cholinesterase inhibition in birds caused by dietary insecticide exposure
Ecological Modelling, 1998
We describe a stochastic simulation model that simulates avian foraging in an agricultural landscape to evaluate factors affecting dietary insecticide exposure and to predict post-exposure cholinesterase (ChE) inhibition. To evaluate the model, we simulated published field studies and found that model predictions of insecticide decay and ChE inhibition reasonably approximated most observed results. Sensitivity analysis suggested that foraging location usually influenced ChE inhibition more than diet preferences or daily intake rate. Although organophosphorus insecticides usually caused greater inhibition than carbamate insecticides, insecticide toxicity appeared only moderately important. When we simulated impact of heavy insecticide applications during breeding seasons of 15 wild bird species, mean maximum ChE inhibition in most species exceeded 20% at some point. At this level of inhibition, birds may experience nausea and/or may exhibit minor behavioral changes. Simulated risk peaked in April -May and August-September and was lowest in July. ChE inhibition increased with proportion of vegetation in the diet. This model, and ones like it, may help predict insecticide exposure of and sublethal ChE inhibition in grassland animals, thereby reducing dependence of ecological risk assessments on field studies alone.
Ecotoxicology (London, England), 2001
We studied the exposure and effect of the organophosphate insecticides azinphos-methyl and diazinon on adult California quail (Callipepla californica) in an apple orchard in the Okanagan Valley, British Columbia. Cholinesterase activity was measured in plasma samples (n = 65) collected from 54 individuals either prior to spraying, immediately (< 24 hours) or 10 days after three spray events. Mean plasma cholinesterase levels declined significantly (P < 0.05, n = 12) to 61% of pre-spray mean activity (controls) immediately following the first spray event, but by ten days had recovered to 86% of mean control activity. Subsequent spray events caused no significant declines in mean plasma cholinesterase activity. Four of the 26 quail sampled within 24 h of a spray event exhibited plasma-ChE inhibition exceeding 50% inhibition. Radio-tagged quail (n = 25) were monitored throughout the breeding season to determine use of orchards and detect changes in use patterns resulting from the...
Emu, 2009
Cholinesterase-inhibiting pesticides are applied throughout Australia to control agricultural pests. Blood plasma cholinesterase (ChE) activity is a sensitive indicator of exposure to organophosphorus insecticides in vertebrates. To aid biomonitoring and provide reference data for wildlife pesticide-risk assessment, plasma acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities were characterised in nine species of native bird: King Quails (Excalfactoria chinensis), Budgerigars (Melopsittacus undulatus), White-plumed Honeyeaters (Lichenostomas penicillatus), Yellow-throated Miners (Manorina flavigula), Willie Wagtails (Rhipidura leucophrys), Australian Reed-Warblers (Acrocephalus australis), Brown Songlarks (Cincloramphus cruralis), Double-barred Finches (Taeniopygia bichenovii) and Australasian Pipits (Anthus novaeseelandiae). Plasma ChE activities in all species were within the range of most other avian species and all but one contained AChE and BChE; no AChE was present in King Quail, which has not previously been reported for any species. The lowest detectable plasma AChE activity was 0.10 mu mol min(-1) mL(-1) in Budgerigars and the highest was 0.86 mu mol min(-1) mL(-1) in Australian Reed-Warblers. BChE in the plasma ranged from 0.37 mu mol min(-1) mL(-1) in Double-barred Finches to 0.90 mu mol min(-1) mL(-1) in White-plumed Honeyeaters and Australian Reed-Warblers. The lowest proportion of AChE was found in Budgerigars (12.8%) and highest in Willie Wagtails (67.8%). No differences were detected in ChE activity at any time of day in Budgerigars and Zebra Finches (Taeniopygia guttata), although there was a significant difference in all ChE activity between seasons in Zebra Finches.
Cholinesterase (ChE) response and related mortality among birds fed ChE inhibitors
Archives of Environmental Contamination and Toxicology, 1975
Patterns of mortality and inhibition of brain and plasma ChE in birds treated with ChE inhibitors were studied in an attempt to determine the validity of using ChE activity as a monitoring and diagnostic technique. Analysis of brain ChE activity proved to be reliable for diagnosing and monitoring effects of selected ChE inhibitors in birds. Brain ChE inhibition exceeding 20% indicated exposure, and inhibition greater than 50% was sufficient for diagnosing cause of death. Individuals that died from dietary exposure to parathion or carbofuran had brain ChE activities below 55% of normal; although individuals could survive with brain ChE activity lower than 50%. Problems associated with collection, storage, and analysis of tissues for ChE activity are discussed.
Environmental Toxicology and Chemistry, 2005
Northern cardinals (Cardinalis cardinalis) frequently use agricultural field edges in northeast Arkansas, USA, and may be at risk of exposure to cholinesterase (ChE)-inhibiting pesticides. We monitored northern cardinal exposure to ChE-inhibiting pesticides by comparing plasma total ChE (TChE) activity to reference-derived benchmarks and TChE reactivations. Total ChE and acetylcholinesterase (AChE) were measured for 128 plasma samples from 104 northern cardinals from nine study sites. Of birds sampled from sites treated with ChE-inhibiting pesticides, 4.3% of the samples had TChE activities below the diagnostic threshold (2 standard deviations [SD] below the reference mean) and 8.7% of the samples had TChE reactivations. No difference was found in TChE (p ϭ 0.553) and AChE (p ϭ 0.288) activity between treated and reference sites; however, activity varied among treated sites (p ϭ 0.003). These data do not suggest uniform exposure to individuals, but rather exposure was variable and likely influenced by mitigating factors at individual and site scales. Furthermore, monitoring of TChE reactivation appeared to be a more sensitive indicator of exposure than the diagnostic threshold. Fluctuating asymmetry (FA) was greater at agricultural sites than reference sites (p ϭ 0.016), supporting the hypothesis that FA may be useful for assessing a combination of habitat-and contaminantrelated environmental stress.
The perfect threat: Pesticides and vultures
Science of The Total Environment, 2019
Probably the most important threat currently affecting vultures worldwide is exposure to pesticides, both accidentally and through deliberate abuse. This is of special concern since around 70% of vulture species are threatened by human activities. However, information about this threat is sparse and geographically biased. We compiled existing knowledge about pesticide exposure in vulture species globally, providing unifying criteria to mitigate this problem with a joint global effort. Most information available about accidental exposure to pesticides in vultures is related to organochlorine pesticides. Non-lethal exposure to these compounds occurs on every continent that vultures inhabit. While concentrations of organochlorine pesticides reported in different samples appear to be too low to produce health impacts, some studies show vultures with levels compatible with health impacts. In addition, there are some reports of vultures contaminated accidentally by anticoagulant rodenticides and external antiparasitic drugs used in veterinary practices. Deliberate abuse of pesticides to poison wildlife also occurs on every continent where vultures live, affecting most (78%) vulture species. However, little information is available for some regions of America, Asia and Europe. The exact number of vultures killed due to deliberate poisoning with pesticides is not well known, but the available figures are alarming (e.g. up to 500 individuals in a single event). The most widely used pesticides affecting vulture populations, and associated with deliberate poisoning, are carbamates and organophosphorus compounds. Of particular concern is the fact that massive poisoning events with these compounds occur, in some cases, within protected areas. This suggests that if this situation is not reversed, some vulture populations could disappear. A combination of measures such as banning pesticides, controlling their distribution-acquisition and environmental education could produce better results that banning pesticides alone. If poisoning with pesticides is not stopped, this threatened avian group could inadvertently go extinct very soon.
Journal of Clinical Toxicology, 2015
Objective: Wildlife death from organophosphate and carbamate pesticide exposure has been documented previously in Canada. Wildlife exposure to these agents can occur through primary toxicity (i.e., inhalation), ingestion of contaminated water or food, or secondary toxicity through scavenging on toxic carrion. This paper describes epidemiologic information pertaining to confirmed acetyl cholinesterase inhibitor pesticide lethality in the coyote and bald eagle over a 16-year period in the Canadian Prairies. Methods: Epidemiologic case information from the diagnostic records of Prairie Diagnostic Services confirmed lethal acetyl cholinesterase inhibitor poisoning in 58 coyotes (Canis latrans) and 60 bald eagles (Haliaeetus leucocephalus) from 1998 to 2013. Brain acetyl cholinesterase enzyme activity suppressed to 50% or greater was indicative of toxicity and death. Results: Coyote case submissions varied both annually (p<0.0001) and temporally (p<0.0001). Submissions were highest in the years of 2000, 200, and 2002 (collectively 46.6%). The months of most frequent submission were May and April (36.2%). Bald eagle cases were also influenced annually (p<0.0001) and temporally (p<0.0001). Confirmed poisoning in bald eagle carcasses was most frequent during two seasonal periods: May through April and December through January. Years 2000, 200, and 2004 comprised 43.3% of the bald eagle poisonings during the investigational period. Annual and temporal distribution of coyote and bald eagle cases were comparable but were not significantly correlated. Brain acetyl cholinesterase activities within 20% of the mean in unaffected cases were considered background. These activities were 3.44 ± 1.52 μmol/min/g in the coyote and 15.18 ± 3.37 μmol/g/min in the bald eagle. Conclusion: Poisoning in wildlife with acetyl cholinesterase inhibitor pesticides continues to be a regular occurrence in the Canadian prairies. Increased surveillance and monitoring of pesticide use should be considered to mitigate future poisonings.