The purpose of this study is to examine some factors that make a human grouse hunter to prolong and increase its hunting effort. The theory of optimal foraging is used for explaining their behavior. The data of this study is collected from a web-based inquiry from 2007 answered by grouse hunters in Sweden. The method that has been used is mainly bivariate statistics and logistic regression analysis. Key findings shows that an experienced grouse hunter has more than 5 times the chance of prolonging hunting effort when grouse density is high, compared to a beginner grouse hunter. On the same time experienced grouse hunters also stop hunting in advance when grouse density is low to a larger extent than inexperienced hunters. Other factors of importance for prolonging the hunting effort for a day are age and the travel distance to the hunting area. A hunter in the age of 35-60 years has got half the likelihood of prolong a good hunting day, compared to a hunter younger than 35 years old. A hunter that has travelled more than 300 km to the hunting area has got half the likelihood of prolonging, compared to a hunter with less than 300 km from its home adress to the hunting area. Conclusions: The result suggests that the behaviour of an experienced hunter is easier to explain by optimal foraging theory than less experienced hunters.