If scavenger birds are declining in a forest area, which role will be a conservation concern?

Correct answer: Natural cleaning of dead organic matter

The direct answer is A: natural cleaning of dead organic matter. Scavenger birds feed on dead animals and other organic remains. Step by step: an animal dies → its body becomes dead organic matter → scavengers consume and remove much of it → decomposition and nutrient cycling become easier → the surroundings are cleaner and disease risks may be reduced. Option A correctly identifies this ecological service. Option B, making river flow, is not the normal role of scavenger birds; river flow depends on water, slope, channels, and rainfall. Option C, making glaciers, is unrelated to birds and depends on long-term cold conditions and snow accumulation. Option D, deciding forest height, is not a biological function of scavengers; forest structure is influenced by vegetation, climate, soil, and disturbance. A decline in scavengers therefore creates concern about waste removal and ecosystem balance. Memory cue: scavengers clean nature’s leftovers.