as abundance of rodents in the preceding year. In this particular study, it was assumed that a greater abundance of rodents in one year may result in higher birth rates among foxes, which feed on the rodents, and therefore a greater population of one-year-old foxes in the following year. Yearling foxes are not yet experienced enough grouse hunters to be considered "smart". As such, distraction display may be a profitable strategy for the grouse in years following rodent population booms, as there is less risk of encountering a "smart" predator. However, a low rodent population in a given year may result in lower birth rates among foxes for that year, thereby resulting in a higher proportion of older, more experienced foxes in the population in the following year. In such a case, grouse may profit from not displaying, as they are more likely to encounter a "smart" predator. See also Animal cognition Anti-predator adaptation Displacement Mobbing Sexual display Threat display References External links The Birder's Handbook Animal communication Antipredator adaptations Bird behavior Ethology Animal cognition