The reading and lecture both discuss about several behaviors of humpback whale. The author relates these behaviors to that humpback whales is capable to navigate themselves by observing stars during migration. However, the lecture disagrees this theory, he admits that these behaviors are fascinating but they don not have connection with star observation.

To begin with, the author says that humpback whale is intelligent enough to use star to navigate by. In the reading part, it is illustrated that humpback whale’s brain is well-developed, and their cognition is good too. However, the lecturer suggests that there is no certain association between intelligence and the ability of utilizing stars. He strengthens his opinion by an example, he says that some birds, like ducks, can navigate by star, but apparently, their intelligence is not excellent.

Secondly, the author point out that when humpback whales migrate, they tend to move in one straight direction, and it requires some external object, like stars, to guild them. The reading gives an analogy of birds, it says some birds migrate with help of landmarks which can indicate where they are. The lecturer thinks that this analogy is not the truth of humpback whale, he provides another scientific explanation that humpback whale is aware of the magnet-field of Earth. One specific organ within their body make them sensitive to the change of the magnet-field, by leveraging this ability, they can move in one direction without any external object.

Finally, the author posits that the phenomenon is known as spy-hopping which is humpback whales posture their body in vertical with the head point to the sky, indicting they are observing stars. The lecture cast his doubt by bring up the truth that some other animals, like shark, they also do the spy-hopping, but they don’t migrate at all. The spy-hopping of sharks is related to hunting. Moreover the lecturer states that humpback whales spy hop at daytime when there is no any star in the sky.