Birds/bird species behavioral effects

The effects of prior experience on taste preference behavior of the fowl was demonstrated ( ) by the fact that ascending versus descending series of preference test concentrations yield vastly different data. The importance of prior experience was confirmed by Davidson (8 ) who reported on preference behavior of various bird species toward berries and seeds in natural settings. He has suggested that low consumption of a new food item by many bird species for 1-10 days is of no particular significance. Thus, certain avian species may be extremely slow to change their normal feeding habits. 

Food flavor familiarity may be the single, most important factor controlling food preference behavior of wild species (8, 23, 77). Mammals show highest acceptance of familiar foods, but they aTTo tend to sample small amounts of any new food item placed in their environment ( ). Some bird species are extremely resistant to changing their preference behavior for certain food items (83). but there is no compelling evidence proving that food flavor is less important to birds than to mammals (6, 85, 89). For mammals (and possibly birds also), food texture, partlFle size, and feeder location can sometimes produce as much, or more, effect than odor and taste of food (103, 104). 

Like humans, ecosystems are exposed to multiple chemicals at any given time. This implies exposure of individuals, species, and ecosystems. The exposure conditions vary considerably, and are determined by the characteristics of the exposure medium as well as by physiological characteristics and behavior of the exposed species and individuals. The object of concern can be separate species, like protected birds, mammals, or butterflies, or it can be assemblages or communities of different organisms or ecosystems. The concern can pertain to the structure or the function of the system, or both. Stressors like mixture exposures may trigger a multitude of responses in ecosystems, including indirect effects due to changes in competition and predator-prey relationships. 

Researchers were also able to establish the link between declines of other predatory species such as the European sparrowhawk and the use of organo-chlorine pesticides other than DDT. For instance, the cyclodiene insecticides aldrin, dieldrin, and he-ptachlor used as seed treatments caused massive mortality of both seed-eating species and their predators. All of the insecticides had the following points in common they were highly soluble in fats and refractory to metabolism. The impacts on the predatory species typically take place in periods of food stress when fat soluble residues are released from fat stores and returned into general circulation. In a food-stressed individual, the brain remains as the most lipid rich tissue and this is where contaminants move to. Toxicity results when threshold values in brain tissue are exceeded. At sublethal levels, documented effects of cyclodiene insecticides in birds have included changes in their reproductive, social, and avoidance behaviors. 

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