Some animals may even fight to death for their resources. Some plants species release toxins into the soil that prevent other species from growing nearby, restricting the space of the others. Really competition does not help other organisms because, competition is where two or more animals fight some even till death so competition does not help other organisms.
Male buck against another male buck. This frequently happens.
In this photo you see them fighting, what probably happened was the other kangaroo went upon the other kangaroos territory.
In this photo you see them protecting what is theirs.