A herd of sheep move up the mountain to graze during summer and migrated to the valley during winter what type of migration do the sheep follow

Seasonal

Explanation:

The type of migration that the sheep follow is seasonal migration. Seasonal migration is one that is dependent on the seasons of the year. In this type of migration, animals move to different areas depending on the time of year. This usually occurs because the animals look for the most suitable places in which their subsistence would be guaranteed.

They migrate due to altitudes during different times of the season