useless trivia: What Word Means: An American Song Bird?

Questions

in the arctic, the ---------- sometimes appears to be square?

in the arctic, the sun sometimes appears to be----------?

in the---------- , there are oysters that can climb trees?

in the caribbean, there are ---------- that can climb trees?

in the scottish hebrides, an island is defined as being an island only if it is big enough to sustain 1----------?