Female parental care (maternal care) appears to be logical and more prevalent in animals than male parental care (paternal care) and these differences in parental investments of men and women are associated with differences in their reproductive investments (Trivers, 1972). However, there are many vertebrate species in which males contribute significantly to parental care (Nunes et al., 2001; Chen et al., 2007). Male parental care appears rare in internally fertilized animals (Duellman and Trueb, 1994) and is more likely to evolve in externally fertilized species (Gross and Shine, 1981; Beck, 1998). But another school of thought predicts that the evolution of parental care depends more on the cost/benefit ratio than on the method of fertilization (Beck, 1998). Apparently, the evolution of paternal care depends on a) the mode of fertilization, b) territoriality and c) the choice of female partner or female fertility (Ridley, 1978; Gross and Shine).,