in the soil. Soil moisture extremes, either wet or dry, which pre- 

 vent the development of new roots could conceivably reduce the leaf 

 content of essential elements. 



*************** 



BIRD DAMAGE RESEARCH IN MASSACHUSETTS 

 Frederick Greeley and Donald Chubbuck 



Research on nuisance species of birds has been conducted in 



Massachusetts for at least 15 years by several agencies federal, 



state and private. The species studied are characterized by either 

 population or behavior which has, in variable degree, exceeded levels 

 of human tolerance. Virtually all the species, whether introduced 

 from other countries or native, have become nuisances as a result 

 of environmental changes induced by man. The Herring Gull, once 

 rare in Massachusetts, has increased in numbers (to the point of 

 being hazardous to aircraft) because of increased food sources at 

 garbage dumps, fish wharves and the like. Breeding habitat for 

 Baltimore Orioles, Robins and European Starlings has increased with 

 the expansion of suburbs with their lawns (feeding areas for Robins 

 hunting earth worms), shade and ornamental trees, and houses (nesting 

 support for all three). These three species are all natural feeders 

 on fruits, whether wild or commercial. At the University of Massa- 

 chusetts, basic research on fruit depredation and on the ecology of 

 Robins and Baltimore Orioles has been conducted for a number of years 



While we have not uncovered, here or elsewhere, any sure econom- 

 ic means of preventing birds from damaging fruit, we have gained some 

 knowledge pertaining to the problem. Most fruits ripen after young 

 birds have taken wing from the nest and become a part of a population 

 in Robins, for example, most of the birds we have observed in Uni- 

 versity orchards are young-of-the-year . We, therefore, are inclined 

 to ask, "How far do they come from, how do they find their way to 

 sources of fruit, and how do they recognize ripeness and edibility 

 of fruits in their first encounter with it?" So far, at least, our 

 studies of the dispersal of marked Robins from their nests indicate 

 they may not travel any farther than need be to find an abundant 

 fruit supply. At the University, the young of one nesting population 

 were able to find a non-commercial source within a half mile of the 

 nests in which they hatched. Although the University orchard, with 

 its cherries and blueberries, was only one mile away, few of these 

 young birds ever appeared there. This suggests that suburban areas 

 in which fruiting species of trees and shrubs were used as part of 

 the ornamental and shade-tree community might divert Robins from com- 

 mercial orchards by holding them closer to nesting areas in the rip- 

 ening season. 



It is difficult to determine how young Robins find their way to , 

 sources of fruit and other food but a few of our observations indicati 



Assoc. Prof, and Graduate Student, respectively, Dept. of Forestry 

 and Wildlife Management, University of Massachusetts. 



