A stand of Douglas fir trees is home to 3 similar species of small insect-eating birds. They eat a variety of insect species: one insect burrows into the tree bark, one lives in the tree needles (leaves), and one flies between trees. All three bird species are able to eat any of the insect species.
If one bird species eats only insects in the tree bark, another forages only in the needles, and the third only catches insects as they fly between trees, then the birds are experiencing:

A. resource partitioning.
B. character displacement.
C. mimicry.
D. predation.
E. intraspecific competition.

A. resource partitioning.

Explanation:

Resource partitioning refers to as the division of limited food or resources by organisms in order to prevent competition in an environment. In situations where there are limited resources or food available to organism s in an ecological niche, such organism in that niche will need too develop strategic ways to coexist and to prevent competition, so that the resources can be shared across.

The birds illustrated in the question above are therefore experiencing resource partitioning.

"it built up in the atmosphere"

i think thats it, idk, i tried looking for this exact q& a for grad. and idk if i got this question right or sorry if im wrong

answer; aerobic conditions; citric acid cycle (krebs cycle) electron transport chain;         anaerobic conditions; fermentation; both glycolysis;