Watch How Rescued Elephants React When They Hear Their Captive Friends Nearby

In the heart of the Mae Teng Valley in northern Thailand, there are more than a dozen elephant "trekking" camps that offer rides through the forest to tourists perched on the backs of Asian elephants. These elephants are often treated poorly and taken from the wild at a young age. Among all of these camps, however, is one sanctuary where elephants roam free.

The Elephant Nature Park in Chiang Mai, Thailand, has rescued over 37 elephants, many of them disabled, orphaned or blind. Some come from trekking camps, others from working in the logging industry, and still others from tourist attractions on the streets of busy cities. But despite their newfound freedom, these elephants can still recognize their captive counterparts.

In fact, elephants at the sanctuary often encounter groups of trekking elephants walking by. Elephant Nature Park's founder, Lek Chailert, told The Dodo in an email that they see these groups walking across the river every day, and they can hear the other elephants coming from as far as a half mile away.

"Sometimes they run to each other and hug each other," Chailert, who grew up in Thailand and founded the sanctuary in 1996, said. "The baby who doesn't have a mother will run across the river to our herd. To see our herd protect them is really heartbreaking. Sometimes they talk from opposite sides of the river. They put their trunks up searching."

You can see one of these encounters in this video - the sanctuary elephants are seen rushing over to where they hear the captive elephants walking through the bush.

About ten of the elephants living at the sanctuary once lived with those elephants that walk by. "Some of our elephants have friends who still work in the nearby trekking camps," Chailert said.

Life is bleak for trekking elephants at the camps that surround the sanctuary - Chailert noted that they can often hear "trumpeting and screaming" from the nearby camps.

The best way to close trekking camps like these are to not visit them, and to support sanctuaries instead. See this guide to responsible elephant tourism in Africa and Asia for more information about how to travel and help elephants.