Abstract: Sexually selected traits may often signal direct (territory, resources, parental care) or indirect (genetic) benefits for a potential mate. In this study, we are most interested in the direct benefit of parental care. There are two hypotheses that predict the relationship between attractiveness in mates and their parental care: the good parent hypothesis and the differential allocation hypothesis. The good parent hypothesis predicts a positive correlation between ornamentation and parental care, and mate choice is based on direct benefits, while the differential allocation hypothesis shows a negative correlation and mate choice is based on indirect benefits. In birds, males more commonly exhibit ornamentation and females prefer males with more enhanced ornamentation. We were interested in size and ornamentation as these traits. In our study species, the dark-eyed junco (Junco hyemalis) the body plumage is mostly gray with the exception of a white breast and white outer tail feathers ("tail white") in both sexes. Males have more white in their tails than do females, and females seem to prefer "tail white" in males. The function of ornamentation and size in females as well as its relationship to parental care is virtually unexplored. Here, we focused on incubation, which is performed only by females in the dark-eyed junco. In order to determine the relationships among ornamentation, size and incubation quality, we first digitally photographed the four outermost tail feathers and assessed the area of "tail white". We filmed incubation watches to evaluate incubation quality. We then evaluated the relationship between both sexes' ornamentation and incubation quality. The results of this study may helped us to better understand if "tail white" and size are signals in juncos and what effect this has on the mate they obtain. The unexpected frequency of mate feeding we found enabled us to make conclusions about the relationship between male size, age and their increased parental investment behavior of mate feeding, thus supporting the differential allocation hypothesis of sexual selection.