TPO 49 integrated writing skill

According to the reading passage, author lists three theories to support that humpback whales may be navigating by the stars, since, lecturer holds opposite view and he states passage's theories are not convincing. Also, he points out some competing theories, which contradict passage's arguments.
Firstly, the essay assumes that humpback whales seem to be intelligent enough to use stars to navigate by. However, the listening material claims that there are other animals using stars to navigate such as ducks, although ducks are not intelligent. Thus, there is no connection between intelligence and navigating by stars.
Secondly, the writer indicates that because humpback whales migrate straight lines for long distances, so, they orient themselves by some external objects or forces and probably they rely on stars at night to navigate. On the contrary, the speaker argues that animals send external forces by assistance earth's magnetic fields, which is called biomagnetic. Therefore, biomagnetic suggests that they orient themselves by magnetic fields rather than navigating by stars.
Finally, the passage discusses that humpback whales sometimes exhibit an unusual behavior, which is known as spy-hopping, means they float straight up for minutes at a time for looking at the stars. In contrast, in the listening section, he reckons that sharks exhibit the same behaviors, but they do not use stars for navigate. Consequently, spy-hopping in humpback whales is not related to navigation, instead, it has other functions.