The African pig-nosed frog, Hemisus marmoratus, provides parental care in terrestrial breeding chambers. While in amplexus, the female digs into the ground where she forms an underground breeding chamber and lays the eggs in a compact mass. The male leaves the chamber after fertilizing the eggs, and the female attends the eggs and developing tadpoles. Wager (1929) excavated two empty chambers and suggested that the female later digs a tunnel towards the water for the tadpoles. The tadpoles would presumably wriggle down this tunnel to reach the water where they would undergo further development and metamorphosis (Wager, 1952, 1965). The tunnel building scenario proposed by Wager (1929) is reiterated throughout the literature (i.e., Lambiris, 1989; Duellman and Trueb, 1994; Crump, 1995), even though it apparently was never observed. Van Dijk (1985, 1997) rejected Wager's scenario as speculative because he encountered tadpoles in flooded depressions without raised banks where the mode of tunnel building suggested by Wager was impossible. The presence of tadpoles in rock pools, artificial ponds, and nests up to 100 m away from the nearest water body in the Comoe National Park, West Africa (R6del et al., 1995) also required that alternative strategies of tadpole guidance be considered. Alternative strategies include flooding of the nest chamber (Van Dijk, 1985), the transport of eggs and tadpoles by the female (Bourquin, 1985; Van Dijk, 1985; Duellman, 1993b; Van Dijk, 1997), and the construction of a surface slide (Rodel, 1996; Spieler, 1997). In order to make sense out of this controversy, we report our observations of reproductive timing and nest construction in H. marmoratus, and, in particular, how tadpoles of this species reach open water from underground nests. Hemisus marmoratus is one of eight species within the single genus in the family Hemisotidae (Duellman, 1993a), endemic to tropical and subtropical sub-Saharan Africa (Savage, 1973; Duellman, 1993b). Three to five subspecies of H. marmoratus (Frost, 1985) are recorded from savannas throughout the geographic range of this family (i.e., Stewart, 1967; Schiotz, 1969; Lambiris, 1989; Passmore and Carruthers, 1995; Rodel, 1996). Hemisus marmoratus sudanensis is found in the Comoe National Park, West Africa (Rodel et al., 1995). This 11.5 km2 park is located in the north-eastern part of the Ivory Coast between 8?5' and 9?6' N and 3?1' and 4'4' W at an altitude of about 250 m (Poilecot, 1991). The southern end of the park, where we conducted our research, is dominated by shrub-tree savannas with scattered island forests and is character-