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Description:
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Chlorpyrifos exposure and effects in passerines and anurans were examined in a series of experiments . European starling Sturnus vulgaris ) nestlings were used as a surrogate to study the effect of chlorpyrifos application to a com acroecosystem on songbird reproduction . Chlorpyrifos was applied in a T -band at label rates ; residues were measured in soil , earthworms , ground -dwelling insects , and diet items collected from the crop of starling nestlings . Chlorpyrifos was detected in all matrices . Nestling brain and plasma cholinesterase (ChE ) activity and body mass measurements were taken at 3 , 8 , and 13 days post -hatch (DPH ) . There were no significant differences in reference vs . treatment brain or plasma ChE activities of 3 , 8 , or 13 DPH nestlings . Body mass differences between treatment and reference site nestlings at 3 and 13 DPA were not significant (a = 0 .05 ) . However , 8 DPH nestlings from the treatment site had a transient reduction in weight (p = 0 .03 ) when compared with 8 DPH reference nestlings . Adult starling fecundity measures (i .e . , clutch size , hatching percentage , and fledging percentage ) indicated that chlorpyrifos application did not significantly affect starling nestling survival to fledging . This screening -level study suggests that although one age group of starling nestlings from the treatment site weighed less than their reference site counterparts , a single T -band application of chlorpyrifos did not impair starling nesting success . |