In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.

Passage: The birds lived in forests at both montane and lowland elevations – they are thought to have moved seasonally, living at higher elevation in summer and descending to lower elevation in winter. Huia were omnivorous and ate adult insects, grubs and spiders, as well as the fruits of a small number of native plants. Males and females used their beaks to feed in different ways: the male used his bill to chisel away at rotting wood, while the female's longer, more flexible bill was able to probe deeper areas. Even though the huia is frequently mentioned in biology and ornithology textbooks because of this striking dimorphism, not much is known about its biology; it was little studied before it was driven to extinction.
The huia is one of New Zealand's best-known extinct birds because of its bill shape, its sheer beauty and special place in Māori culture and oral tradition. The bird was regarded by Māori as tapu (sacred), and the wearing of its skin or feathers was reserved for people of high status.
What are thought to have moved seasonally, living at higher elevations in summer?