For example , females of nearly all shorebirds have longer bills than males of the same species , and female American avocets have beaks which are slightly more upturned than those of males .
This allows the sexes to utilize different ecological niches , thereby reducing intraspecific competition .
Females of nearly all shorebirds have longer bills than males of the same species , and female American avocets have beaks which are slightly more upturned than those of males .
This allows the sexes to utilize different ecological niches , thereby reducing intraspecific competition .