Damage to Maturing Apples by Birds 



James A. Parkhurst 



Department of Forestry and Wildlife Management, University of Massachusetts 



Results from recent research in the Hudson Valley 

 of New York may be of interest to producers of early- 

 maturing apple cultivars. Using a variety of survey 

 techniques together with on-site inspections at 13 or- 

 chards, researchers from Cornell University and the 

 USDA Denver Wildlife Research Center evaluated the 

 nature, extent, and severity of bird damage to ripening 

 apples (condensed from Tobin, M. E., R. A. Dolbeer, 

 and P. P. Woronecki. 1989. Bird damage to apples in 

 the mid-Hudson Valley of New York. HortScience 

 24:859). 



When asked to evaluate the extent of damage 

 attributable to birds on maturing apples (within 1 to 14 

 days of harvest), growers responded that less than 1 % 

 of their apples were affected, and at only four sites was 

 damage believed to exceed 10 % overall. In contrast, 

 researchers found evidence of bird damage (peckings) 

 in 57 % of the trees that they sampled during on-site 

 inspections, and nearly 6 % of all apples had been 

 pecked. Common crows were identified as being re- 

 sponsible for most damage, although a host of other 

 species were suspected (including house finch, Ameri- 

 can goldfinch, cedar waxwing, blue jay, common 

 grackle, and European starling). Because their re- 

 search was conducted in orchards with known damage 

 (i.e., a non-random sample), these researchers believe 

 that their figures represent the extreme rather than a 

 regional average. Regardless, their estimates point out 



that growers may be underestimating the extent of 

 damage. 



Of greater significance were findings that the tim- 

 ing of fruit maturation and fruit color may affect bird 

 depredation. Early-maturing cultivars (e.g., Jersey- 

 mac, Jonamac, Paulared, and Tydeman) sustained the 

 greatest amount of damage from birds. Late-maturing 

 cultivars that exhibited a red coloring earlier in the 

 season (e.g., Cortland, Empire, and Rome) also were 

 damaged. In every case where bird depredation was 

 recorded, a blush of red was found on the affected 

 apple. 



Although pockets of exceptionally high damage 

 may exist locally, these researchers maintain that bird 

 depredations are of minor concern regionally. Of 

 greater concern is the evidence that damage may be 

 focused on early-maturing cultivars, particularly in 

 light of the current trend toward, and increasing acre- 

 age in, these cultivars. 



If you believe that you are experiencing problems 

 with bird depredations, you may contact the USDA 

 APHIS Animal Damage Control office in your state for 

 on-site technical assistance and control suggestions. 

 Requests for animal damage control information and 

 educational programs may be directed to your Coop- 

 erative Extension office or through your local Coopera- 

 tive Extension agent. 



22 



Fruit Notes, Summer, 1990 



