In the vast grasslands, a familiar ecological scene unfolds: cattle egrets closely following grazing cows. As cows move through the grass, they disturb and expose insects, making them easy prey for the egrets that trail behind. This fascinating interaction is a classic case of commensalism—a type of symbiotic relationship where one species benefits while the other is neither helped nor harmed.

How the Relationship Works

• Benefit to Egrets: Cattle egrets feed on insects and small creatures that are flushed out by the movement of grazing cows. This gives the egrets easy access to food that would otherwise be difficult to find or catch.

• Effect on Cows: The cows continue their normal grazing behavior, unaffected by the presence of the egrets. They do not gain any significant benefit nor do they suffer any disadvantage from the egrets feeding nearby.

Why This Is Commensalism

• Definition: In commensalism, one organism benefits while the other is not significantly impacted.

• Egret-Cow Example: The egret benefits by gaining food, and the cow is unaffected. This is distinct from mutualism (where both benefit) or parasitism (where one is harmed).

Occasional Mutualistic Aspects

In some cases, egrets may also pick off ticks or other pests from the cows, offering a minor benefit to the cattle. However, the primary and most common interaction is commensalism, as the main advantage is to the egret, and the cow’s well-being is largely unchanged235.

Conclusion

The relationship between cattle egrets and grazing cows is best described as commensalism. The egret gains food, while the cow is unaffected by the egret’s presence. This interaction is a classic example used in ecology to illustrate commensal relationships in nature.

Correct answer: (1) Commensalism235.