Source: The Wilson Journal of Ornithology 127 (4), 730-733, DEC 2015
Brief summary of the paper: Sex roles during incubation vary dramatically in socially monogamous shorebirds. The “incubator conspicuousness” hypothesis posits that, for biparentally incubating and sexually dimorphic birds, the more conspicuous sex should incubate when visually foraging predators are inactive, and in many ecosystems this is at night.
Therefore, sexually monomorphic species should share incubation equitably throughout the day and night. We examined incubation patterns in Masked Lapwings Vanellus miles and found that the contribution of the sexes to incubation was equitable.
Another measure of incubation behavior, bout duration, was similar between the sexes; male bout durations were slightly shorter than for females.
This finding is consistent with the predictions of the incubator conspicuousness hypothesis, although other processes may also explain equitable care.