Which of the following investigations is an example of the study of an abiotic factor? A. the relationship between finch beak size and food availability on two different Galapagos IslandsB. observing interactions among various organisms in a rainforest canopyC. investigating how an elk population competes for foodD. identifying food sources for an egret populationE. investigating how the amount of annual precipitation affects the distribution of a tree species

E. Investigating how the amount of annual precipitation affects the distribution of a tree species.

Step-by-step explanation:

Abiotic factors are factors in an ecosystem that are non-living. Abiotic factors include water, soil, temperature, light, and air. Among all the choices, only choice E considers an abiotic factor, which is precipitation.

Precipitation is water, and as mentioned earlier, water is an abiotic factor. The case here is the study of the annual precipitation and effects on distribution of species. The study is specific to the precipitation.

The other choices involve biotic factors, like food source, the organisms and the like.