Without wolves, the health of forests suffers. what theme of biology does this demonstrate?

The relationship between the wolves and the forest is symbiotic and precisely a mutualistic relationship. Mutualism is relationship between two species in which both are benefited.

Example: The maned wolf feeds on birds, rodents and sometimes fishes but maned wolf majorly feeds on plants and especially lobeira or wolf apple is a yellow and red fruit like tomato. When the maned wolf fed only on meat in zoo it developed stones in bladder which disappeared on including plant based food in their diet. The lobeira fruit seed carried by the wolf to several locations broadens the territory of lobeira plants and shows a mutualistic relationship between the wolf and the plant.

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