Avian studies

Most avian studies of protein turnover have been carried out using the domestic fowl, and the tissue most studied has been skeletal muscle. Growing birds (domestic fowl, ducks and turkeys) accumulate... 

In contrast to the mammalian and avian studies, the available information on the metabolism of the spinosyns by insects suggests that metabolism of the spinosyns (e.g., spinosyn A) is very limited. Studies of spinosyn A metabolism in tobacco budworm Heliothis virescens) larvae show that the only component detected (within the limits of detection, up to 24 h post treatment) in larval homogenates of topically treated larvae was the parent, spinosyn A [53, 54]. In contrast, these same larvae readily metabolized the acaricide fenazaquin [3, 53], clearly demonstrating that H. virescens larvae have the capacity to metabolize xenobiotics. Further, studies with H. virescens larvae highly resistant to spinosad [55] also found no evidence for metabolism of spinosyn A [56, 57]. 

Most avian studies emphasize ingestion as the primary route of exposure to toxic metals, because other routes of exposure are extremely uncommon. Because risk of exposure is greatly influenced by bird feeding and nesting habits, the characteristics of birds need to be taken into account for any study and its subsequent results. Age and sex differences in uptake and distribution of metals also influence metal exposure. Ultimately, even the same species of bird may behave differently in different environments, creating variations in risk of exposure (20). 

Cholinesterase and ATPase are enzymes also effected by metal exposure, though few avian studies have investigated the mechanisms of response. Dieter... 

Incorporation of artificial nest boxes in avian studies attracts cavity-nesting birds to the site and provides an easily monitored environment. Some species of birds are more easily examined from boxes than others. Blue birds and tree swallows tend to nest sporadically throughout a site, while starlings nest in groups and breed synchronously. Arrays of boxes can be set up on different sites in an area, thereby allowing birds to be monitored at the same time, which yields consistent changes of prey item differences within a season. Birds that do not breed synchronously can be useful in identifying exposure differences over time in the same area. 

In addition to obtaining adequate vvind resources, site selection sites for wind turbines must also consider avian populations. Several studies have been performed to determine the impact that turbines have on bird populations, with inconclusive results (Sinclair and Morrison, 1997). However, siting turbines to avoid nesting and migration patterns appears to reduce the impact that turbines have on bird mortality. 

Avian Effects Assessment A Eramework for Contaminants Studies... 

The effect of probiotic use in chicken production has also been studied by several groups. For example, Kralik el al. (2004) have studied the effect of adding probiotics to the drinking water of avian broilers. They reported an increase of live weights of broilers, an improvement in feed conversion ratios and lower population densities of the pathogenic bacteria E. coli and Staphylococcus aureus in the intestinal contents. 

No data are available on the toxicity of copper to avian wildlife. All studies with birds and copper use domestic chickens, ducks, or turkeys (Table 3.6). Copper, however, may indirectly affect avian wildlife by curtailing certain prey species. Winger et al. (1984), for example, show that apple snails (Pomacea paludosa) are not only extremely susceptible to copper (LC50 of 24 to 57 pg/L in 96 h immatures most sensitive), but are the primary food of the snail kite (Rostrhamus sociabilis), an endangered species. The decline of the apple snail in southern Florida coincided with the use of copper-diquat to control hydrilla aquatic weeds (Hydrilla verticillata), with serious implications for the snail kite (Winger et al. 1984). 

Data are scarce or missing on copper deficiency effects in aquatic flora and fauna and in avian and terrestrial mammalian wildlife additional studies of copper deficiency in these groups are merited. In sensitive terrestrial agricultural crops, copper deficiency occurs at less than 1.6 mg... 

Carlton, W.W. and W. Henderson. 1964b. Studies on the copper requirement of growing chickens. Avian Dis. 8 227-234. 

Pain, D.J., C. Metayer, and J.C. Amiard. 1993b. Lead determination in avian blood application to a study of lead contamination in raptors from France. Int. Jour. Environ. Anal. Chem. 53 29-35. 

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