Question: Breathing in birds is different than breathing in mammals- air flow over the lungs of birds is un…

Breathing in birds is different than breathing in mammals- air
flow over the lungs of birds is unidirectional. When this was first
discovered, the question arose as to whether gas exchange is
countercurrent, or concurrent. To answer this question, some
researchers did experiments in which they measured the efficiency
of gas exchange between air and blood in duck lungs when air flow
was in its normal direction and when it was artificially reversed.
They found that the efficiency of gas exchange did not change and
concluded that gas exchange in birds is neither concurrent nor
countercurrent. Do you agree with the conclusion that the
researchers made? Explain why or why not.