Minimizing Wildlife Damage

Agricultural losses due to wildlife exceed $3 billion annually in the United States. To reduce this problem, BEHAVE researchers at the National Wildlife Research Center (NWRC) are looking for opportunities to use behavior to prevent damage to crops, nursery stock, ornamentals and seedlings planted for reforestation. BEHAVE research at NWRC is primarily focused on ungulate (animals with cloven hooves) foraging in forest ecosystems and fruit depredation by birds.

Understanding why an animal behaves as it does is the foundation for changing its behavior. In this case, diet and habitat selection depend on an animal’s genetic make-up and its individual and social experiences. Chemicals present in foods drive diet selection by providing feedback from the gastrointestinal tract to the brain. This feedback enables animals to associate sensory attributes of foods (taste, smell, and texture) with the consequences of eating and creates preferences for and aversions to foods. Based on this understanding of diet selection, Dale Nolte, a research wildlife biologist and field station leader at Olympia, WA, and Bruce Kimball, a research chemist at Fort Collins, are exploring potential new tools to reduce damage to agricultural resources.

• Development of New Deer Repellents
• Minimizing Bird Damage to Fruit

Development of New Deer Repellents.

Hydrolyzed casein (a milk product) was demonstrated to be an effective repellent for minimizing deer browse damage to plants of economic and ornamental value.  Pen studies conducted with both white- and black-tailed deer confirmed that plants treated with hydrolyzed casein were strongly avoided by deer.  Furthermore, baby formulas containing hydrolyzed casein were also shown to provide protection against deer browse.  In a field study, hydrolyzed casein reduced deer browse damage to conifer seedlings at reforested sites across the Pacific Northwest and Vancouver Island, BC.

These experiments indicate that hydrolyzed casein is a promising contact repellent. Hydrolyzed casein is water soluble, unlike casein that has not been hydrolyzed, making it easier to produce spray formulations.

Minimizing Bird Damage to Fruit

Mary Cheney, graduate student, is conduting experiments with captive robins and starlings to develop non-lethal techniques to reduce fruit depredation by birds. Result demonstrate that visual cues (i.e. color) are strongly associated with negative consequences paired with illness. Thus, the use of visual cues must be a critical component of any strategy to reduce bird damage to fruit that relies on flavor aversion learning and mimicry.  Another aspect of these experiments, identification of an aversive agent for practical application, demonstrated that robins and starlings can consume large quantities of anthraquinone without resulting in negative consequences.  Anthraquinone, a known aversive agent for birds, may not be suitable for reducing intake of high-energy food sources such as grapes.

Recent Publications

Kimball, B.A.; Nolte, D.L.; and Perry, K.R.  (2005).  Hydrolyzed Casein Reduces Browsing of Trees and Shrubs by White-tailed Deer (Odocoileus virginianus).  HortScience  40: 1810-1814.

Kimball, B.A.; Russell, J.; Griffin, D.L.; and Johnston, J.J.  (2005).  Response Factor Considerations for the Quantitative Analysis of Western Redcedar (Thuja plicata) Foliar Monoterpenes.  J. Chromatogr. Sci.  43:253-258.

Kimball, B.A. and Nolte, D.L.  (2005).  Herbivore Experience with Plant Defense Compounds Influences Acquisition of New Flavor Aversions.  Appl. Anim. Behav. Sci.  91: 17-34. 

Personnel:

Mary Cheney

Research Assistant

Department of Wildland Resources

Utah State University, Logan, UT

Bruce Kimball
Research Scientist, Chemical Ecology
NWRC, Ft. Collins, CO

Dale Nolte
Research Leader, Damage Management
NWRC, Olympia, WA