Eventually his production company decided to prioritise programming for dogs because they are pack animals and suffer most from separation anxiety.

BBC: New TV channel for dogs sets tails wagging in Israel

Schaller himself had attempted to find the calving ground a year earlier, but his trek failed when his pack animals died.

NPR: Chang Tang's Endangered Antelope

In the Middle Ages, European craftsmen refined the design, improving the efficiency and allowing pack animals to do more work with less strain.

FORBES

Some communities are ecologically friendly: they use solar power and green methods of waste removal, undertaking the daunting challenge of hauling non-biodegradable items off the mountain via pack animals as opposed to burning or burying trash.

BBC: Everest's growing problem

Dogs are pack animals and so are humans.

FORBES: What Can An Old Dog Teach Aging Parents?