Anticoagulant rodenticides are widely used to control rodent infestations. Previous studies have shown that nontarget organisms, such as birds, are at risk for both primary and secondary poisoning. This paper presents rodenticide residue information on the livers from 164 strigiformes which included barn owls (Tyto alba), barred owls (Strix varia), and great horned owls (Bubo virginianus), collected from 1988 to 2003 in the province of British Columbia and the Yukon Territory, Canada. Livers were analyzed for brodifacoum, bromadiolone, chlorophacinone, diphacinone, difethialone, and warfarin. Our results show that, of the 164 owl livers analyzed, 70% had residues of at least one rodenticide, and of these 41% had more than one rodenticide detected. Of the three species of owls examined, barred owls were most frequently exposed (92%, n = 23); brodifacoum and bromadiolone were most often detected, with liver concentrations ranging from 0.001 to 0.927 mg/kg brodifacoum, and 0.002 to 1.012 mg/kg bromadiolone. Six of the owls (three barred owls, two barn owls, and one great horned owl) were diagnosed as having died from anticoagulant poisoning; all six owls had brodifacoum residues in the liver.
Wild nestling tree swallows (Tachycineta bicolor) inhabiting reclaimed wetlands receiving tailings or water from mine tailings ponds on oil sands mine sites were the subjects in a multiyear study to determine the ecological viability of these areas. Spanning two field seasons, immune function, reproductive performance (clutch size and mass, hatching success), nestling growth and survival, and diet of tree swallows were examined on six wetlands. One aspect of immune function, the T-lymphocyte proliferative response, was assessed in vivo using a phytohemagglutinin skin test. Hepatic ethoxyresorufin-O-deethylase (EROD) activity provided a biomarker of exposure to oil sands contaminants in the tree swallow nestlings. Results show that there were no differences among reclaimed wetland sites for tree swallow reproductive success, nestling growth rate, and immune response that could be attributed to tailings or tailings pond water additions. Increased EROD activity confirmed the presence of xenobiotics in the diets of nestlings from two sites, while the main reference site was relatively free of EROD-inducing compounds. Dietary analyses showed that 84% of the food items of the tree swallow nestlings were of aquatic origin, likely from the local wetlands, and thus would be expected to provide a good reflection of biological effects of any mining-related contaminants accumulating through the food chain.
Reproduction and biochemical indicators (vitamin A, ethoxyresorufin‐O‐deethylase [EROD], highly carboxylated porphyrins) of contaminant effects, and concentrations of organochlorine residues were measured in tree swallows from wetlands within the watersheds of the Great Lakes and the St. Lawrence River, USA and Canada. To assess the vitamin A sources in the tree swallow diets, insects were collected, by ligature, from nestlings at four of these sites. Diet samples were analyzed for retinol and α‐ and β‐carotene. Marked differences were found in chlorinated hydrocarbon residues in eggs and nestlings among sites; however, we did not find any significant differences in hatching or fledging success. The maximum polychlorinated biphenyl (PCB) concentration found was 11.1 μg/g in eggs from Akwesasne Reserve, New York, USA, on the St. Lawrence River, whereas the highest p, p′‐DDE concentration of 2.57 μg/g was found in eggs from Mud Creek, Ontario, Canada, in the Lake Erie watershed. Concentrations of other organochlorine pesticides and chlorobenzenes were low and not variable among sites. Significant differences in hepatic EROD activity, retinol and retinyl palmitate, and uroporphyrin in nestling birds existed among sites. Ethoxyresorufin O‐deethylase activity was highest and retinol and retinyl palmitate were lowest at Cornwall Island, Ontario, Canada, in the St. Lawrence River, whereas porphyrins were highest at Toronto and Hamilton harbors, Ontario, Canada, in Lake Ontario. Ethoxyresorufin O‐deethylase induction was significantly and negatively correlated with nestling hepatic retinol concentrations, whereas uroporphyrin concentrations were positively correlated with PCB congener 118 in nestlings. In contrast, few differences occurred in vitamin A concentrations in diet samples among sites. Together, these findings suggest that depressed hepatic vitamin A and elevated highly carboxylated porphyrin concentrations are strongly associated with sites with the highest organochlorine exposure in tree swallows.
The main goal of this study was to evaluate a communication assistance device (CAD) for individuals with deafblindness, based on a braille display notetaker connected via Bluetooth to an iPhone. This study examined the use of this device by a 61-year-old woman living with Usher syndrome with sighted and hearing interlocutors during three restaurant outings.The study had three specific objectives: 1) To evaluate the participant's and her interlocutors' perceptions of their productivity in the communication interaction in real-life situations, without and with the CAD; 2) To evaluate the participant's emotional experience after using the CAD; and 3) To describe how the communication interactions between the participant and her interlocutors work, without and with the CAD. The relevance, utility and interest of such a communication support technology became clearly apparent, along with the enthusiasm it aroused in her interlocutors. Despite the empowerment it provided, the huge differences in some aspects of interactions made without and with the CAD suggest that the constraints introduced by the use of a CAD modify the nature of communication. Four recommendations are made. Any future development of the technology intended for users with minimal experience working with computers and electronic devices should be encouraged.
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