Eventually, the male will not have the proper nutrition which makes the male unable to produce sperm. For instance, male amphipods will deplete their reserves of glycogen and triglycerides only to have it replenished after the male is done guarding that mate. Also, if the amount of energy intake does not equal the energy expended, then this could be potentially fatal to the male. Males may even have to travel long distances during the breeding season in order to find a female which absolutely drain their energy supply. Studies were conducted to compare the cost of foraging of fish that migrate and animals that are residential. The studies concluded that fish that were residential had fuller stomachs containing higher quality of prey compared to their migrant counterparts. With all of these energy costs that go along with guarding a mate, timing is crucial so that the male can use the minimal amount of energy. This is why it is more efficient for males to choose a mate during their fertile periods. Also, males will be more likely to guard their mate when there is a high density of males in the proximity. Sometimes organisms put in all this time and planning into courting a mate in order to copulate and she may not even be interested. There is a risk of cuckoldry of some sort since a rival male can successfully court the female that the male originally courting her could not do.