"Nut crops may provide an inexhaustible food supply one year, but no food the following year. Many birds and mammals utilize mast, but the degree to which their population biology is affected by mast availability varies greatly (Christisen and Korschgen 1955, Bock and Lepthien 1976, Ostfeld et al. 1996, Smith and Scarlett 1987). For some, a poor mast crop simply means that the animal must use other food items more than they would if there were a large mast crop (Harlow et al. 1975, Williams and Batzli 1979a). Others rely heavily on mast as a winter food source, and a poor mast crop may lead to reduced survival and perhaps poor reproductive performance (Koenig and Mumme 1987, Wolff 1996)." - Todd Scarlett, 'Where Do All the Nuts Go?', usclancaster.sc.edu.