because they huddle with their families
The larger the bird, the larger its nest.
mild winter to come
The Kiwi is a flightless bird, and must stay on the ground.
The hummingbird builds the smallest nest. Typical hummingbird nests are around 0.79 inches across and 1.18 inches high. Hummingbirds build their nests using mud or saliva.
In summer the temperature reaches as high as 50' and in winter they can get as cold as -20'.
No,bees do it in autumn.
The Colorado Plateau Desert is a high cold winter desert.
It's only cold in winter. The interior of South Africa is a plateau which is high above sea level. The hight is what makes it cold in winter and mild in summer. The Cape is on sea level but it is hit by a lot of cold fronts in winter.
It is generally hot and it is not cold in winter and there is high humidity.
A hoopoe flies. It's a bird and it isn't flightless. Although, they do prefer to stay lower to the ground. They don't build their nests too high in the trees.
Some DO have winter. A desert is defined not by high temperatures, but by lack of water. It can get quite cold in some deserts.
Canadas that do decided to stay a winter in a cold climate do it out of sheer will power. Usually those that do not migrate have a family member that is injured or too old to take the flight. In that case, the entire family stays behind with him/her. High fat content to their bodies, additional down grown for the winter and redundant circulation in their feet help them biologically make it through the cold, but otherwise, from my observation, it is the will of the bird to make it through.