The polyphenol content of three orchard pear varieties, Conference, Doyenne du Comice and Williams bon Chretien as determined between November 1981 and March 1982 as a preliminary part of a study to ascertain the basis of dietary selfselection by bullfinches. The varieties most susceptible to bird damage, Conference and Williams, were shown to contain higher levels of extractable phenolic material than the partly bird-resistant variety, Comice. There were no major intravarietal differences between buds of the same variety collected at different areas of the same site. The significance of these results is discussed.
S U M M A R YDamage to pear trees of the cultivars Conference and Doyenne du Comice caused by Bullfinches feeding on the flower buds was measured during January-April 1981. Bud-eating was concentrated on trees near woodland, and occurred at a steady rate within each row, though progressively more rows were attacked. Levels of total soluble protein, free amino acids, starch, glyceride-glycerol, fructose, glucose and phosphorus were low until mid March, when the amounts per bud (and concentrations of starch and total soluble protein) rose sharply, coinciding with an increase in the size of buds. Sucrose did not occur at detectable levels. Conference buds contained significantly higher concentrations of fructose and free amino acids than Comice. The implications for understanding bullfinches' bud-feeding habits are discussed.
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