Pastoral communities refer to communities that depend on livestock rearing as their primary source of livelihood. These communities typically live in rural areas, often in mountainous regions where the terrain is suitable for grazing animals. In this particular question, all the options mentioned - Gujjars, Gaddis, and Bhotiyas and Sherpas - are pastoral communities of the mountains.

Gujjars:
Gujjars are a pastoral community found in various parts of India, particularly in the states of Jammu and Kashmir, Himachal Pradesh, and Uttarakhand. They are traditionally nomadic herders who rear cattle, sheep, and goats. The Gujjars are known for their expertise in animal husbandry and their ability to navigate and survive in mountainous terrains.

Gaddis:
Gaddis are another pastoral community residing in the mountains of Himachal Pradesh, India. They are predominantly sheep and goat herders and migrate with their livestock to higher pastures during the summer months. Gaddis have a deep understanding of the local ecology and practice sustainable grazing practices to ensure the health and productivity of their herds.

Bhotiyas and Sherpas:
Bhotiyas and Sherpas are pastoral communities found in the mountainous regions of Nepal, Bhutan, and the Indian state of Uttarakhand. Bhotiyas primarily inhabit the border regions of India and Tibet (China) and are known for their skills in yak herding. Sherpas, on the other hand, are mainly concentrated in the Solu-Khumbu region of Nepal and are renowned for their mountaineering abilities, serving as guides and porters for expeditions in the Himalayas.

These communities have a deep connection to the mountains and rely on the resources provided by the high-altitude ecosystems for their sustenance. They have developed unique cultural practices, knowledge systems, and traditional livelihood strategies that are closely intertwined with their natural surroundings.

In conclusion, all the options mentioned in the question - Gujjars, Gaddis, and Bhotiyas and Sherpas - are pastoral communities of the mountains. These communities have adapted to the challenging mountain environments and have developed sustainable ways of living in harmony with nature.