title: Effects of lethal and sublethal concentrations of the herbicide, triclopyr butoxyethyl ester, in the diet of zebra finches.
abstract: Lethal and sublethal effects of dietary triclopyr butoxyethyl ester (TBEE) on zebra finches (Poephila guttata Gould) were determined in laboratory experiments conducted between 8 January and 1 May 1991. The 8-day median lethal dietary concentration, LC50 (95% confidence interval), of TBEE to zebra finches was 1,923 (1,627 to 2,277) mg/kg. In the sublethal effects experiment, when birds were exposed to 500 mg/kg TBEE in the diet for 29 days, food consumption and body weight were significantly depressed (P < 0.05). Similar prolonged exposures to 50 and 150 mg/kg TBEE in the diet had no significant effect on food consumption or body weight (P > 0.05). Perch-hopping activity was depressed relative to controls in the 500 mg/kg group, and elevated in the 150 mg/kg group, but neither of these differences was significantly (P > 0.05). Disappearance of TBEE residues from treated seeds over the 29 day experimental period followed an exponential decay model, with half-lives in the order of 15 to 18 days. On the basis of our observation that TBEE had no significant adverse effects at a concentration greater than the maximum expected environmental concentration, we propose that forestry applications of triclopyr at registered dosage rates pose little risk to wild songbirds.
authors.affiliation: Forest Pest Management Institute, Department of Natural Resources Canada, Ontario.
authors.forename: S B
authors.initials: SB
authors.lastname: Holmes
authors.forename: D G
authors.initials: DG
authors.lastname: Thompson
authors.forename: K L
authors.initials: KL
authors.lastname: Wainio-Keizer
authors.forename: S S
authors.initials: SS
authors.lastname: Capell
authors.forename: B
authors.initials: B
authors.lastname: Staznik
mesh_terms: D000704:Analysis of Variance; D000821:Animal Feed / Q000633:toxicity*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001715:Bird Diseases / Q000139:chemically induced*; D001717:Birds; D001835:Body Weight / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D005260:Female; D005506:Food Contamination; D006016:Glycolates / Q000633:toxicity*; D006540:Herbicides / Q000633:toxicity*; D008297:Male; D010573:Pesticide Residues / Q000633:toxicity; D011897:Random Allocation; D012044:Regression Analysis; D012639:Seeds
chemical_list: D006016:Glycolates; D006540:Herbicides; D010573:Pesticide Residues; C032742:triclopyr