Damage to fruit does not occur randomly. By being familiar with patterns of damage, a grower may be able to reduce damage or the cost of control by concentrating control methods in particular areas and at times of the season when damage is most severe.
Although all farms and orchards are susceptible to damage, it usually is greatest on farms in close proximity to town environments where birds such as robins and starlings are abundant. Damage is generally higher in orchards isolated from other orchards. In large areas of orchards, so much fruit is available that the amount of damage on any one site is fairly low. The size of the orchard also influences the amount of damage. As a pattern, small orchards generally experience a greater degree of damage than large orchards because they have fewer trees. Thus, damage can be an important problem for those who produce fruit on a small scale.
The time at which the fruit matures appears to influence the amount of damage. For apples, bird damage is highest on early maturing varieties. Late varieties that experience damage are primarily ones that turn red early in the season. These patterns suggest that birds are responding to the color change in apples. Bird damage to cherries and grapes is also greatest to early ripening varieties. Early ripening fruit might be damaged more frequently because it matures at a time when other fruits are not available.