The cost to helpers varies depending upon presence or absence of related offspring. The presence of offspring has been found to increase the helper's cost by the helper contributing to guard behaviors. Guarding behaviors, such as babysitting, can cause individuals to experience weight loss on an exponential scale depending upon the duration of the activity. Other activities, such as sentinel behavior and bipedal surveillance, cause helpers to have reduced foraging intervals inhibiting their weight gains. The reduced foraging behavior and increased weight loss reduces their chance to breed successfully, but increases their inclusive fitness by increasing the survival of related offspring.
