Montseras have developed holes because of the lighting conditions they naturally live in. Monsteras grow from the forest floor, vining up to capture the light that enters through the overhead canopy. The only way plants can survive in such environments is by catching as much of the small rays of sunlight that make their way through the canopy. The holes in the leaves are due to the conditions in the deep jungle in which the plant lives in its natural environment. Most of the time, it is hidden from sunlight by the dense crowns of trees and photosynthesis must be done thanks to the bright sun rays, which only occasionally fall on the leaves. These rays pass through the foliage of trees in gusts of wind so that where they will fall is impossible to predict. Monsteras create holes in their leaves to resist strong winds.
Another key reason is holes to allow a better flow of water to their roots. In the tropical understory, flecks of sunlight make it through the canopy intermittently and erratically. The holes allow leaves to spread out over greater areas without needing to expend energy and nutrients growing extra leaf area to fill this space. That, in turn, may improve the plant’s chances of catching sun ray.