Oak trees (genus Quercus) may possess a behavioral defense against acorn predators. Data collected from many oak species shows a common trend that several years of relatively low acorn production are followed by a year with an exceptionally large production of acorns. The term “mast” is used to refer to the amount of acorns produced per year, and the phrase “mast year” is used to describe the year in which acorn production is exceptionally high. Mast years seem to be synchronous within a given population of oaks; most of the trees in a population have high acorn production in the same year. Their are several hypotheses about why mast years occur. The environmnetal conditions to produce flowers or fruit may be exceptionally favorable in
