Male-only parental care is very common in species with external fertilization, such as fish and amphibians. Little is known about facultative parental strategies in the generally non-caring sex. Like in most poison frogs, also in Allobates femoralis the obligatory tadpole transport from terrestrial clutches to aquatic maturation sites is generally performed by males. After oviposition, females abandon their clutch and return to their resting sites, which are located up to 20 m away from male territories. Nevertheless, several anecdotal observations of females with larvae on their back have been reported in the past. During five years of monitoring a natural population we observed 7.8% of tadpole transport performed by females, which we could link to the absence of the respective fathers. In the following removal experiment under laboratory conditions, all tested A. femoralis females flexibly took over parental duties, but only in situations when their mates were missing. The ability to flexibly compensate the loss of the other parent is commonly known in species where both sexes provide care. Our findings demonstrate that compensatory flexibility can occur even in species with uni-sexual parental care. We further tested if A. femoralis males and/or females differentiate between offspring and unrelated young, if they use direct or indirect recognition cues, and whether previous mating success is essential for triggering parental behaviours. We found that males transport tadpoles regardless of location or relatedness, but to a lesser extent when lacking recent mating success. Females discriminated by exact location, but not by relatedness, and performed parental care only when they had previously produced a clutch. We conclude that differential discrimination mechanisms have evolved in response to contrasting reproductive strategies and associated spatial behaviour in both sexes.