Some say dogs are a man’s best friend. But they aren’t the only animals in humanity’s circle of friends. People have cooperated with wild animals throughout our evolutionary history. Biologists refer to these relationships as mutualisms. It means both species benefit.
One such mutualism in Brazil recently made headlines. Local fishers have been catching nets full of fish with the aid of bottlenosed dolphins (Tursiops truncatus gephyreus). This team-up started more than a century ago.
The dolphins and fishers were chasing the same prey — schools of migratory mullet (Mugil liza). Mauricio Cantor is a behavioral ecologist. He works at Oregon State University’s Marine Mammal Institute in Newport. The dolphin partnership probably began when fishers realized the presence of dolphins meant fish were hiding in the murky water, Cantor says.
Educators and Parents, Sign Up for The Cheat Sheet
Weekly updates to help you use Science News Explores in the learning environment
Thank you for signing up!
There was a problem signing you up.
“The dolphins are really good at detecting fish and herding them toward the coast,” he notes. “The fishers are really good at trapping the fish with their net.” Once those fish are mostly secured in the net, dolphins can move in and snag some for themselves.
Cantor is part of a team that used long-term data to show that the dolphins and fishers respond to cues from each other. Without experienced partners who know the right dance steps, this routine falls apart. Cantor’s team described this mutualism January 30 in the Proceedings of the National Academy of Sciences.
“This is a really remarkable and impressive study,” says anthropologist Pat Shipman. She works at Pennsylvania State University and was not involved with the research.
This mullet-fishing partnership is an important part of the cultural identity of both the fishers and the dolphins. However, Cantor and his colleagues show, the practice is in decline. And among human-animal partnerships, it’s not alone. “Most of the historical cases are declining or already gone,” Cantor says.
Given their rarity and charm, let’s look at some other examples of human-animal cooperation.
Killer whales had helped human whalers
The bottlenosed isn’t the only dolphin with which humans have joined forces. People used to team up with a type — orcas, also known as killer whales — to hunt other whales in southeastern Australia.
Back in the 1800s, whaling crews hunted in southeastern Australia’s Twofold Bay. These crews included Aboriginal Australians and Scottish immigrants. Several hunters began working with a pod of orcas (Orcinus orca) to catch large whales. Some orcas would find and harass a whale to tire it out. Other orcas swam to alert the human hunters that they’d found prey.
The whalers would show up and harpoon the whale. Then they would let the orcas eat the tongue before taking the rest of the carcass for themselves. Whale tongue is a delicacy in the orca diet.
Here, the orcas and whalers were mostly after different things. But as with the dolphins and fishers in Brazil, Cantor says, there’s enough prey for everyone. No competition arises to spoil the partnership.
This relationship ultimately ended when some settlers killed two orcas. This drove the cooperative pod away from the bay. It seems they never hunted with humans again.
This bird may guide people to honey in Africa
A name sometimes says it all. Such is the case for a bird known as the greater honeyguide (Indicator indicator). These birds, which live in sub-Saharan Africa, take both their English and Latin names for their most famous trait. They cooperate with local honey hunters. In return, the birds gain access to succulent beeswax.
Like people, these birds don’t like to be stung by bees. When a honeyguide gets a hankering for beeswax, it will chirp at people to signal they should follow it. The honeyguide then leads the hunters to a bee’s nest. It then lets people do the dirty work of harvesting it.
Sometimes the signals are sent the other way. The Borana people of East Africa blow a special whistle called a “fuulido.” Its sound summons the honeyguides when it’s time for a honey hunt.
As with orcas, honeyguides and humans are after different parts of the prize. People are after the honey. Birds seek the wax.
Similar to the dolphins in Brazil, the relationship with honeyguides is an important part of many African cultures. Legends warn against denying a honeyguide its beeswax. A scorned honeyguide is said to lead the hunters not to delicious honey but instead into the jaws of a dangerous predator, such as a lion.
Wolves and people once teamed up to hunt big game
To see the most extreme outcome of a human-animal partnership, take a look at 39 percent of the country’s beds, couches and backyards. That’s about how many households in the United States own a dog. But canines don’t need to be domesticated to get along with people. Indigenous stories from peoples in North America describe cooperating with gray wolves (Canis lupus). Together they hunted big game, from elk to mammoths.
The wolves would run down the prey until it tired. Once the humans caught up, these people would make the kill. These prey were massive. So it didn’t matter that humans and wolves were after the same thing. There was plenty of meat to go around.
Although wolves are still important in many Indigenous cultures, this furry friendship exists no more. After a hunt, some peoples do, however, continue leaving a bit of meat for the wolves.
Human-animal partnerships have been rare throughout history. But they “give us an illustration of how positive our human interactions can be with nature,” Cantor says.
For Shipman, the urge to engage with animals is a defining trait of humanity. “It’s in some ways as fundamental to humans,” she notes, “as being bipedal.”