I am interested in the relative importance of male participation in parental care strategies and hence, the general importance of males for the stability of monogamous mating systems. Male parental care is rare in most animals; however, bi-parental care is more pervasive in birds than any other vertebrate class. Research on male parental care has focused primarily on the nestling stage, while care during incubation has received less attention. The only empirical studies of male-shared incubation have focused on three north temperate species; all of which demonstrated that males spend less time on the nest and were less efficient at maintaining incubation temperatures than females. However, because life-history strategies of tropical birds are vastly different from those seen in north-temperate birds, we need to examine male-shared incubation in a broader context. In many endemic tropical families the relative importance of male-shared incubation in entire clades remains totally unstudied. Consequentially, geographic and phylogenetic variation in male-shared incubation, and questions about how male incubation efficiency, and hence relative investment may influence selection for biparental care remain to be explored further. Specifically, I investigate male-shared incubation in two endemic tropical, cloud forest species; the Slaty Antwren (Myrmotherula schisticolor) and the Plain Antvireo (Dysithamnus mentalis). Our study aims at elucidating patterns that will allow us to test future hypotheses on variation in tropical life history strategies.