Complex sentence: This dual mechanism theory in birds raises the questions, if such a mechanism is actually responsible for magnetoception, to what degree is each method responsible for stimulus transduction, and how do they lead to a tranducible signal given a magnetic field with the Earth's strength.
Split into simpler sentences: This dual mechanism theory has been proposed in birds and the question that arises, if such a mechanism is actually responsible for magnetoception, is to what degree each method is responsible for stimuli transduction. Regardless of the importance of either of these mechanisms, an issue they must both address is how they lead to a tranducible signal given a magnetic field with the Earth's strength.