PARENT SESSION
Oral Session #14: Invasive species: Effects.
Presiding: S. DeSimone
Monday, August 5. 1:00 PM to 3:45 PM. Greenlee Meeting Room, TCC.
Using basic ecological information to control impacts of rock squirrels (Spermophilus variegatus) in pecan plantations.
HERNÁNDEZ, LUCINA*,1, LAUNDRÉ, JOHN1, MARTINEZ, MAGDELENA2, COLODNER, GABRIELA1, ARCINIEGA, BRENDA2, LEGARREDA, DIANA2, 1 Instituto de Ecología, A.C., Aldama, Chihuahua, Mexico2 Universidad Autonoma de Chihuahua, Chihuahua, Chihuahua, Mexico
ABSTRACT- Often basic ecological information is used to enhance populations. However, often the problem is not too few but too many individuals of a species, resulting in conflicts with human activity. A case in point is rock squirrels in pecan plantations in northern Mexico where owners claim they inflict extensive economic loss. Our objective was use a multi-step ecological approach to the problem. First we assessed the extent of the problem by comparing productivity of trees exposed to and protected from squirrels, using feeding trays to assess foraging patterns of squirrels, and calculating potential pecan consumption based on energetic needs of squirrels. Next we measured soil texture, vegetation structure, soil pH, and micro surface complexity to determine which may enhance the use of the area by squirrels. Lastly, we tested if modification of factors found to be important could be used to reduce the number of squirrels in the plantation. Preliminary results indicate no effect of squirrels on per tree nut productivity. Feed tray results indicate squirrels forage primarily in the periphery of the plantation. Energetics calculations indicate only extremely high squirrel numbers would inflict significant economic loss. Results of the habitat study soil texture and micro surface complexity (tree branches, soil mounds, etc.) contribute to the presence of squirrels in an area. Overall results indicate that basic ecological information can be used to evaluate and if necessary, control a problem species.
KEY WORDS: Spermophilus variegatus, pecans, impacts, control