Cite an example to explain why species interactions are conditional and dynamic

Mutualism is a way of life in which two species that could live independently come together permanently or sporadically and each one puts something on their side for the survival of both. In nature there are many types of mutualism, for example, the spider and the toad, the narrow-billed toad is an ally of a type of tarantula that usually devours small frogs, but what, in exchange for this small amphibian to eat the parasites that affect its eggs, the arachnid allows it to live in his burrow underground and in return defends him from possible predators, like owls, throwing to them urticating hairs in their eyes.

The interaction between two species can change over time, depending on their habitat and availability of resources. The change may also be triggered by human intervention, urbanization, reproductive behavior and shifting weather condition. One of the best examples we can use is the relationship between ants and aphids. Ants protect aphids from predators, and in return, they get rewarded with honeydew, a substance produced after aphids feed on a part of a plant. They peacefully coexist together until the environmental condition changes. Once the ants find better sources of carbohydrates,  they prefer to predate the aphids instead of harvesting honeydew.