text: An Emlen funnel is most often used to study behavior linked to this phenomenon.
full_question: An Emlen funnel is most often used to study behavior linked to this phenomenon. The forebrain regionCluster N may assist this process through a quantum-entangling radical pair mechanism induced bycryptochrome activation in the retina. Anxiety during this process is called Zugunruhe. Vagrants can resultfrom defects in this process such as spring overshoot. The trigeminal nerve is thought to facilitate this processby transducing signals from magnetite-based receptors in the beak. Planetarium studies show that in somespecies it may be performed using celestial navigation. The record for this yearly action is held by the arctictern. For 10 points, name this mass seasonal movement undertaken by geese.
first_sentence: An Emlen funnel is most often used to study behavior linked to this phenomenon.
raw_answer: bird migration [or migrating; prompt on orientation; prompt on animal behavior until "behavior" is read; prompt on navigation until it is read]