In experimental research, scientists tend to assume that—unless they are looking specifically at reproduction or sexual behavior—male and female animals are alike, and mostly use males. But a new study by researchers at the University of California, Davis and the University of New Hampshire, published April 18 in Scientific Reports, shows surprisingly big differences in tissue gene expression between male and female rock doves. The work is part of an attempt to make science more gender-inclusive and aware of physiological and other differences between the sexes.