If a group of mantella frogs were transported to the ecosystem of the poison dart frogs what might happen to the two species' population

The Mantella frog of Madagascar and the poison dart frog of South America share the same characteristics but they live in different ecosystems. The two frogs live in the same type of niche, eat the same type of food and have similar defense mechanisms. Therefore, if a group of mantella frogs are transported to the ecosystem of the poison dart frogs, the two populations will be involved in competitive exclusion, that means that, both frogs will fight for the same resources and the better suited frog will survive. Thus, the population of the ill suited frog will decrease.